Transportation Glossary

The following is a listing of transportation-related terminology and phraseology developed by CCMPO.
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Term	Acronym	Definition
10 MPH Pace Speed		10 mph range in which the majority of vehicles are traveling.
3C's Process	3Cs	A federally-mandated (via the Federal-Aid Highway Act of 1962) initiative, requiring a "Continuing, Cooperative, & Comprehensive" transportation planning process to be carried out by states, regions, and local communities.
3PL Provider	3PL	A third-party or outsourced freight management service provider, customizing shipping, warehousing, and administrative logistics activities.
4A's of the Federal-Aid Highway Program	4As	The process of funding highways that are desginated as part of the Federal-Aid System; Authorization, Appropriation, Apportionment, Allocation
4PL Provider	4PL	Similar to a 'Third-Party Logisitcs' (3PL) service provider, a 4PL specializes in expertise in the design of 'Supply Chain Management' systems, but has no freight moving assets (e.g. warehouses or infrastructure) of its own.
511	511	National traveller information phone number designated by the FCC.
811	811	Underground damage prevention system (e.g. electric, natural gas, telephone, cable, etc.) information phone number designated by the Federal Communications Commission (FCC). In Vermont, this service is known as "Dig Safe".
85th Percentile Speed		The maximum speed at which 85% of all vehicles are travelling.
Access Management	AM	Techniques of Transportation infrastructure management intended to; reduce congestion and accident rates, lessen need for highway widening, conserve energy, and reduce pollution. Examples include; limiting entrance and exit of traffic on highways, use of medians and turn lanes, placement and timing of signals, as well as implementation of supportive local ordinances.
Accessibility		The facilities and services that make it possible to get to any destination, measured by the availability of physical connections (roads, sidewalks, etc.), travel options, ease of movement, and proximity of destinations.
Act 200		Otherwise known as the Vermont Growth Management Act of 1988, Act 200 originally contained 4 "Process Goals" and 32 "Planning Goals", which were paired down to 12 Goals in 1990, then increased to 13 in 2003. This law established mechanisms to help integrate Local, Regional, & State perspectives during the planning process, as well establish consideration of the "spillover effects" of land use decisions of one municipality upon another. A major objective of Act 200 was to ensure that decisions were made at the most local level possible.
Act 250		A Vermont State land use law that requires a permit from the District Environmental Commission or the Vermont Environmental Board prior to commencing a major development or subdivision on a property.
Advanced Traffic Management System	ATMS	ITS applications designed to enhance traffic movement usually along transportation corridors.
Agency of Natural Resources	ANR	A cabinet-level Vermont state agency that oversees environmental issues for the state and is responsible for SIP adoption (T3 VSA, Chapter 51).
Aggregate		Any of various loose, particulate materials such as sand, gravel or pebbles used in a road aggregate base or surface layer of a road.
Airport Improvement Program	AIP	FAA program that assists the development of public-use airports by providing funding for airport planning and development projects.
Airport Information Management System	AIMS	An annually updated database of airport project descriptions, costs, and scoring factors of capital projects negotiated with the Federal Aviation Administration (FAA).
Albany-Bennington-Rutland-Burlington-Essex	ABRB-E	Congressional earmarked project, authorized in SAFETEA-LU intended to enhance Vermont's rail infrastructure on the Western Vermont Corridor.
Alternatives Analysis	AA	A study which explores the effect of a project on the overall transportation system. Information included in an AA are costs, benefits, and impacts of potential changes to the transportation system.
American Association of Railroads	AAR	Association members include primary freight railroad companies in the U.S., Canada, and Mexico, as well as Amtrak.
American Association of Retired Persons (Formerly)	AARP	Established in 1958, AARP (formerly known as the American Association of Retired Persons, but is simply "AARP" today to reflect that membership is possible for non-retirees also) is a US-based non-governmental organization, non-profit, advocacy, and lobbying group for people age 50 and over.
American Association of State Highway and Transportation Officials	AASHTO	Publishes standards for transportation infrastructure for use throughout the U.S.
American Community Survey	ACS	An ongoing nationwide survey that produces about U.S. population and housing. The ACS replaces the decennial census long form questionnaire (from the year 2000 and back), which collected this data every 10 years.
American Institute of Certified Planners	AICP	A non-compulsory planning certification recognized in the United States.
American Planning Association	APA	A nonprofit education and membership guild for professional planners.
American Public Works Association	APWA	Chartered in 1937, the APWA is the international educational and professional association of public agencies, private sector companies, and individuals dedicated to improving public works goods and services.
American Recovery and Reinvestment Act of 2009	ARRA	A $787 billion Recovery plan includes federal tax cuts and incentives, an expansion of unemployment benefits, and other spending on social entitlement programs. In addition, federal agencies are using Recovery funds to award contracts, grants, and loans around the country. The Recovery Act was intended to jumpstart the economy but many of the projects funded by Recovery money, especially those involving infrastructure improvements, are expected to contribute to economic growth for many years.
American Society of Civil Engineers	ASCE	ASCE is the oldest national engineering guild in the United States, founded in 1852 at the offices of the Croton Aqueduct, New York City (originally formed as the American Society of Civil Engineers and Architects). ASCE is comprised of Regional Councils, Younger Member Councils, Sections, Branches, Student Chapters and Clubs, International Student Groups. ASCE posits its mission as "making this a better world by design".
Americans with Disabilities Act	ADA	Federal legislation passed in 1990 that prohibits discrimination on the basis of disability.
Ancient Roads		According to Act 178: an 'Act Relating to Unidentified Corridors' (otherwise known as the 'Ancient Roads Bill') of the Vermont General Assembly, an Ancient Road is an Unidentified Corridor, which would be eligible to become a Class IV Road under applicable criteria. Unidentified Corridors are town highways that: 1. Have been laid out as highways by proper authority through the process provided by law at the time they were created or by dedication and acceptance; and 2. Do not, as of July 1, 2009, appear on the town highway map prepared pursuant to section 305 of this title (Sec. 1. 19 V.S.A. § 302); and 3. Are not otherwise clearly observable by physical evidence of their use as a highway or trail; and 4. Are not legal trails.
Annual Average Daily Traffic	AADT	A key statistical indicator for roadway counts (i.e. traffic volume), known as the 'Annual Average Daily Traffic', or AADT, has been developed to represent the average amount of vehicular traffic in both directions of travel, passing on a given point of road, over a 24-hour period, on a typical day (i.e. seasonally adjusted) of a specified year.
Apron		See; "Truck Apron"
Arc/Info		Geographic Information System (GIS) software for database development and management.
ArcView		Windows-based Geographic Information System (GIS) for the layperson to use geographical data.
Arterial Street or Highway		A major street or highway. It is a general term which includes expressways, major and minor arterial streets and interstate, state or county highways having regional continuity. It is a road intended to move a relatively large volume of traffic at medium to high speeds.
Articulated Bus		Segmented bus that has rear portion flexibility, but is permanently connected to a forward portion and has no interior barrier to hamper passenger movement between the two portions. The advantage to this type of vehicle is that seated capacity is increased up to 60-80 people, and a superiour turning radius (diminished off-tracking) to that of a standard bus.
Asphalt Concrete	AC	A macadam or petroleum based, flexible substance used in roadway surface construction (also known as "tarmac" - i.e. tar macadam).
Attainment Area		Air quality designation where measures of selected pollutants do not exceed established (NAAQS) standards.
Automatic Traffic Recorders	ATR	A pneumatic triggered device, utilizing rubber tubes installed upon a roadway to count, classify, and record speed data. ATRs are the tool used to capture Total Vehicle volume (used to calculate AADT), truck & bus data, 85th percentile & 10 MPH pace speed data, et al.
Automatic Vehicle Identification	AVI	A type of ITS, AVI generally signifies the recognition and recording of motor vehicles, usually automobiles, as they pass through facilities for automatic collection of tolls, thus eliminating stops.
Automatic Vehicle Location	AVL	A system which tracks real-time location of fleet vehicles to assist in dispatching.
Backhaul		Describing the return trip of a transportation vehicle (rail, truck, or container). Backhaul often refers to a lower revenue-generating leg of a shipment haul, because the vehicle is either empty or partially loaded.
Ballast		Crushed angular stone used to distribute the heavy loads of moving locomotives and their freight, facilitate drainage, and reduce vegetation growth along a railroad bed.
Basic Freeway Section		The area of freeway between interchanges or weaving areas. Where the term "Freeway" refers to a divided highway with full access control and 2 or more lanes in each direction for the exclusive purpose of moving traffic, consisting of 1. "Basic Freeway Sections", 2. "Weaving Areas", and 3. "Ramp Junctions". A Basic Freeway Section serves no access function and is separated from on and off ramps. It is often called a "Pipeline" or "Main Pipeline".
Better Backroads Program		A program of the USDA, the Better Backroads Program has been in existence since 1997, focusing on correction of road-related erosion problems for towns. Promotion of the program is handled via technical and financial assistance.
Bill of Lading		Same as 'Waybill'.
Blue Ribbon Commission on Innovative Finance	BRC	Initiated with a workshop at the University of Vermont campus in June 2007, the charge of the Commission on Innovative Finance is to provide a set of recommendations regarding viable innovative finance strategies to advance the regions' transportation needs, including all modes (especially public transportation)as well as the necessary connections with our land use, economic, environmental and quality of life needs. The Commission has since drafted recommendations to be phased into policy over time.
Bollard		A wooden or metallic post installed at the entrance of a bikepath or pedestrian way intended to restrict motor vehicle access.
Bottleneck		A metaphorical expression indicating a narrowing or reduction of roadway capacity due to; construction, maintenance, congestion, accidents, infrastructure (e.g. bridges, tunnels, reduced lanes, etc.).
Breakbulk		Non-containerized freight, or the process of breaking down cargo from a shipping container
Bridge Program		Federal funding program for rehabilitation and reconstruction of bridges.
Buildout Analysis		A form of analysis predicting the total amount of development that could possibly occur in a given area under existing or proposed legal constraints (e.g. zoning ordinance) and environmental constraints (e.g. wetlands, floodplains, steep slopes, etc.).
Bureau of Transportation Statistics	BTS	The Bureau of Transportation Statistics (BTS) was established by the Intermodal Surface Transportation Efficiency Act of 1991. BTS administers federal transportation data collection, analysis, and reporting resources.
Burlington International Airport	BIA	Burlington International Airport is the preeminent Airport in the State of Vermont, located in South Burlington and owned by the City of Burlington.
Bus Rapid Transit	BRT	Fixed-route bus system operating on its own exclusive "Right of Way".
Byways		America's Byways is a registered umbrella term used to promote a collection of distinct and diverse roads, designated by the U.S. Secretary of Transportation as a National Scenic Byway. Further, there are also state-designated Byways in Vermont, which may or may not have national designation.
Calcium Carbonate	CaCO3	Gravel, dirt, or recycled asphalt roads have an increased durability when treated with Calcium Carbonate. Usually applied in a liquid or flaked solid form, it penetrates and coats the road aggregate mixture (i.e. various sized particles such as gravel or sand), binding it together to retain road density, compaction, and moisture level. This increases the roadway resistance to wear, reduces dust generation and erosion of the road surface.
Calcium Chloride	CaCl2	Calcium Chloride (CaCl2) is an extremely effective de-icing agent, which melts snow or ice at temperatures as low as -22°F. Although it lowers the freezing point of water further than traditional road salt (NaCl), it is more expensive and requires special handling. Calcium Chloride has also been associated with the needle browning of pine trees.
Calibration		The process of developing the model parameters using observed transportation data (e.g. traffic counts). Model calibration optimizes the agreement between observed data and the model’s predicted data.
Campus Area Transit System	CATS	The University of Vermont’s fare-free shuttle system serving the University community—faculty, staff, students, and visitors. This system links all on-campus destinations and provides evening service to adjoining neighborhoods. Ridership during the school year averages 4,000 to 5,000 per day.
Campus Area Transportation Management Association	CATMA	Organization formed by several institutions in Burlington’s 'Hill Institutions' to jointly address localized transportation, commuter, and parking issues.
Capacity		A transportation facility's (road, railway, etc.) ability to accommodate a moving stream of people or vehicles in a given time period.
Capital Improvement Program	CIP	A multi-year plan, which identifies equipment, infrastructure, property improvements, or other tangible purchases, as well as their schedule and financing strategies.
Capture Rate		The percentage of vehicles which pass a Park & Ride facility, which could be influenced to use it.
Carbon Monoxide	CO	A colorless, tasteless gas produced primarily by inefficient combustion of organic fuels in transportation and industrial activities. Overly high levels of CO reduces oxygen in the bloodstream, preventing normal respiration. CO emissions are regulated by the Agency of Natural Resources.
Carshare		An alternative to standard car ownership, "Carsharing" offers a means to potentially reduce costs and pollution by renting automobiles on a short-term basis (often by the hour) for the occasional user, utilizing a decentralized parking system called "pods" (often established along transit routes). Carsharing organizations (CSO's) further administer membership bases, vehicle reservation systems, maintenance, and other administrative functions.
Catch Basin		A catch basin is designed to trap debris so that it will not enter the stormwater drainage system. They are often buried drainage structures that are often placed at regular intervals along the edge of the roadway. Proper placement of catch basins can reduce roadside hazards associated with deep drainage ditches near cross culverts. Catch basins should be deep enough to allow for the collection of gravel and debris and should be inspected and cleaned regularly to prevent collected debris from being washed into connecting culverts or water bodies. Catch basin covers should be selected based on ability to pass debris and not pose a safety hazard to vehicles, bicycles or pedestrians.
Catchment Area		An area of increased influence for use of a site, facility, market, or corridor.
Categorical Exclusion	CE	Federal and State regulations (see; NEPA) require environmental reviews to be performed before expenditure of public funds can be approved for "major projects." If a project does not meet the definition of "major project" then it may be eligible for what is called a Categorical Exclusion (CE). A CE is the absolute lowest level of environmental review possible for projects. For Vermont transportation projects, VTrans (The State DOT) is responsible for such designation.
Census Transportation Planning Package	CTPP	CTPP is a demographic dataset intended for transportation planners, which is taken from decennial census. From 1970 to 2000, the CTPP and its predecessor (the UTPP) used data from the decennial census long form (i.e. a component questionaire of the census form sent to 1 in 6 households in Vermont). The CTPP is therefore a sample dataset of the total population. CTPP 2000 has three parts; Part 1. Residence end data summarizing worker and household characteristics, Part 2. Place of work data summarizing worker characteristics, Part 3. Journey-To-Work commuter flow data (which commuties workers live and work within).
Centerline		The middle of a right-of-way, not considering direction or number of lanes.
Central Business District	CBD	Often the geographic center or 'downtown' secton of a city, town, or village, typifying a concentration of commercial, government, residential, and mixed-use buildings or development
Channelization		Separation of conflicting traffic movements into defined paths of travel to facilitate the safe and orderly movement of vehicles, pedestrians, and bicycles.
Chicane		A traffic-calming measure employing fixed objects (usually curbs, earth, fencing, etc.), which deliberately project into the travel lane or a road or shared-use path creating a curvature pattern in the line of travel.
Chittenden County Metropolitan Planning Organization	CCMPO	The State’s only MPO. Established under federal law and responsible for transportation planning and programming within its jurisdiction.
Chittenden County Regional Planning Commission	CCRPC	Land use planning agency for Chittenden County, Vermont
Chittenden County Transportation Authority	CCTA	Operator of Chittenden County’s regional bus system and rideshare services. Chartered in 1973 by the Vermont General Assembly, CCTA serves the communities of Burlington, Essex, South Burlington, Shelburne, Williston, Winooski and a portion of Colchester. There are also express route service to Montpelier, Middlebury, and St. Albans.
Chittenden Traffic Alert	CTA	A countywide and regularly updated listing of construction projects and special activities affecting transportation facilities throughout the region. Each Friday between April and November the CCMPO publishes “Construction This Week” in the Burlington Free Press to alert the traveling public to roadway work.
Class of Railroad		Originally defined by the Interstate Commerce Commission (which was disbanded in the mid-1990's), Class of Railroad generally refers to a railroad company's size in terms of its average annual operating revenue. Specific figures (in 2001 dollars), outlining 'Classes' 1-3 are: Class 1 = railroads with an operating income above $256m (many miles of track, serving many states with a fleet of locomotives sometimes in the thousands), Class 2 = railroads with an operating income of $40m - $256m (regional railroad serving a few states with perhaps 30-200 locomotives), Class 3 = railroads with an operating income of $20m or less (typically operates only in one state, has only a handful of locomotives, usually operating less than 200 miles of track).
Class of Road		Vermont State classification of roads based on level of traffic and percent of the state-aid apportionment for town highways. For example, apportionment a town's Class 2 roads is determined by the town's percentage of all Class 2 town highway mileage in the entire state (see: VSA Title 17, Chapter 3, § 306 Appropriation). The scheme may be expressed as: Class 1 = 6% of state annual highway appropriation, Class 2 = 54% of state annual highway appropriation, Class 3 = 50% of state annual highway appropriation, Class 4 = 0% of state annual highway appropriation. Local selectpersons determine which highways are class 4 town highways. State = State highways are those highways maintained exclusively by the Agency of Transportation.
Class of Track		A Federal Railroad Administration (FRA) track designation, establishing maximum authorized speed for passenger and freight trains, whilst placing requirements on the track maintenance criteria, vehicle standards, and train control signal systems. The maximum speed, outlined in Track Classes 1-9 (freight speed/passenger speed) are: Class 1 = 10/15mph, Class 2 = 25/30mph, Class 3 = 40/60mph, Class 4 = 60/80mph, Class 5 = 80/90mph, Class 6 = 110/110mph, Class 7 = 125/125mph, Class 8 = 160/160mph, Class 9 = 200/200mph.
Class of Vehicle		An FHWA vehicle classification scheme distinguishing 14 categories, depending on whether the vehicle carries passengers or commodities.
Clean Air Act Amendments of 1990	CAAA	Federal legislation that sets allowable levels, known as NAAQS, for various pollutants. Where these standards are not attained, officials must take specified actions within a mandatory time frame or face sanctions such as loss of federal highway funds.
Cold Start		The starting of an engine which is significantly below normal operating temperature, of significance in understanding vehicle emissions since the rate and composition of emissions vary with engine temperature. Often the most polluting time of car operation.
Collector Street or Highway		A street or highway that provides for traffic movement between major streets (major corridors or arterials) and local streets. A collector is a road intended to collect traffic from local streets and land-access roads. The term -Collector Highway- does not include a city street or local service road or a country road designed for local service and constructed under the supervision of local government.
Commercial Drivers' License	CDL	A CDL is required for those operating any type of vehicle with a Gross Vehicle Weight of 26,001 lbs. or greater (such as; tractor trailers, buses, and tow trucks).
Commercial Vehicle Operations	CVO	An Intelligent Transportation Systems (ITS) application for advanced technologies in commercial vehicle operations, including; Satelite Navigation & Real-time monitoring, Load-Tracking Systems, International Border Crossing Clearance, Commercial Vehicle Electronic Clearance or Screening, Automated Roadside Safety Inspection, Automated fuel & mileage reporting, Hazardous Material Planning and Incident Response, et al.
Commodity Flow Survey	CFS	Primary source of national and state-level data on domestic freight shipments by American establishments in mining, manufacturing, wholesale, auxiliaries, and selected retail industries.
Commuter Rail		Generally applies to multi-car, high-speed rail transport utilizing exclusive, frequently at-grade, rights-of-way with service between urban areas or between outlying suburbs and the urban core. Usually involves greater distances and fewer stops than those normally found with light and heavy rail transit within urban areas.
Commuter Shed		Usually refering to a catchment area for a Park & Ride facility, or the origin and destination patterns of commuters along travel corridors or routes.
Complete Streets		Coined in 2003 by bicycle and pedestrian advocates, "Complete Streets Design Techniques" are employed to enable safe access for all users. Pedestrians, bicyclists, motorists and transit riders of all ages and abilities must be able to safely move along and across a "Complete Street".
Compressed Natural Gas	CNG	Fuel for natural gas powered vehicles (primarily buses). Natural gas is comprised mostly of methane that is compressed (about 2,400 lbs. per square inch) and stored in high-pressure design containers.
Conformity		The requirement that the state or metropolitan transportation plan, programs, and projects are consistent with the purpose of the State Implementation Plan (SIP). The CAAA does not permit federal approvals of funding of any project that does not meet this test.
Congestion		A condition which hinders movement on a transportation facility at optimal legal speeds. Frequently characterized by unstable traffic flows.
Congestion Management Process	CMP	Formerly known as a Congestion Management System (CMS), CMP is a federally-mandated program within Metropolitan Planning Organizations to address and manage congestion.
Congestion Management System	CMS	A systematic process for managing congestion and enhancing mobility through alternative transportation strategies and timely information to the traveling public.
Congestion Mitigation and Air Quality	CMAQ	A program authorized by the 1991 ISTEA provided billions of dollars in funding for surface transportation and other projects that contribute to air quality improvements and reduce traffic congestion. The CMAQ program has been improved and reauthorized in all subsequent federal transportation re-authorization bills.
Congestion Pricing		Charging users of a transportation network during peak periods of traffic, in order to reduce traffic congestion and pollution.
Consumer Price Index	CPI	Calculated monthly by the Federal Bureau of Labor Statistics (BLS), the Consumer Price Index (CPI) is a measure of the average change over time in the prices paid by consumers for a representative basket of goods and services. The CPI is used for a number of purposes, such as; An economic indicator of the effectiveness of economic policy, A method to adjust dollar values for economic inflation or deflation, et al.
Container-on-Flatcar	COFC	A shipping container capable of transport upon a rail flat car or truck flat bed trailer. Same as TOFC.
Containerization		The practice of using International Organization for Standardization (ISO) Containers as a unit in transport of freight. Containers are strong enough for repeated use, can carry goods on truck, rail, seabourne, and airborne modes, and are outfitted with devices for efficient modal shift. Standard containers come in five general sizes; 20 ft., 40 ft., 45 ft., 48 ft., and 53 ft. Capacity is often expressed in twenty-foot equivalent units (see TEU).
Context-Sensitive Solutions	CSS	The process of CSS seeks to preserve aesthetics, historical context, and environmental resources in areas of proposed development, while maintaining efficiency and safety of the transportation system. It is a collaborative and interdisciplinary approach, involving a variety of stakeholders to develop facilities and infrastructure in harmony with their current physical setting.
Continuous Traffic Counters	CTC	Operated by VTrans, CTCs are permanently deployed traffic counters, which are capable of collecting traffic data for an entire year or longer.
Continuous Welded Rail	CWR	Superior to traditional "jointed track", where rails are bolted together, CWR provides superior strength for higher speed locomotives and requires less maintenance.
Contraflow Lane		Otherwise known as a "reversible lane", it is utilised for buses where the direction of travel is opposite to the flow of traffic in the other lanes. Contraflow lanes are also employed for maintenance purposes, or in cases of emergency evacuation where both sides of an interstate highway are used for outbound traffic.
Coordination		Comparisons of transportation-planning materials on one agency with those of other agencies and subsequent adjustment of these materials to reduce omissions, duplications, and conflict.
Corduroy Road		In the context of Ancient Roads, a "Corduroy" road is a road built using tree logs as a sub-base where logs or poles layed crosswise. Such roads were common to moisture prone locations.
Corner Sight Distance	CSD	The minimum distance a driver can see across an intersection corner in tandem with the length of time it takes the driver to safely traverse the intersection (past potential crossing vehicles) on to the roadway, and accelerating up to traffic flow speed.
Corporate Average Fuel Economy	CAFE	Automobile manufacturer vehicle fleet fuel economy standards. More specifically, CAFE is the sales weighted average fuel economy, expressed in miles per gallon (mpg), of a manufacturer’s fleet of passenger cars or light trucks with a gross vehicle weight rating (GVWR) of 8,500 lbs. or less, manufactured for sale in the United States, for any given model year. Fuel economy is defined as the average mileage traveled by an automobile per gallon of gasoline (or equivalent amount of other fuel) consumed as measured in accordance with the testing and evaluation protocol set forth by the Environmental Protection Agency (EPA). The “Energy Policy Conservation Act,” enacted into law by Congress in 1975, added Title V, “Improving Automotive Efficiency,” to the Motor Vehicle Information and Cost Savings Act and established CAFE standards for passenger cars and light trucks. The Act was passed in response to the 1973-74 Arab oil embargo. The near-term goal was to double new car fuel economy by model year 1985.
Corridor		A geographic area that is defined by major highway and rail facilities, and major flows of travel. Transportation corridors are identified for the purpose of analyzing the patterns and flows of traffic between origins and destinations.
Crossdock		Operations in a warehouse not relating to storage, where freight is shifted from different trucks to consolidate loads for immediate shipping.
Crown		A roadway crown is the high point located at the centerline of the road with a uniform slope of surface toward each shoulder. The purpose of the crown is to create a natural means of drainage for stormwater to flow off of the roadway surface. A properly shaped crown facilitates this flow in uniform, thin sheets, thus preventing scour and washout of the roadway surface or seepage into the subbase. A paved road generally has a cross slope of 2% (or 1/4" decline per foot from crown to shoulder). An unpaved road generally has a cross slope of 4% - 6% (or 1/2" - 3/4" decline per foot from crown to shoulder).
Culvert		Often constructed out of steel, concrete, plastic, or PVC, a culvert is conduit infrastructure used to channel water underneath and away from a road or railway embankment.
Cumulative Impacts		The impact on the environment which results from the incremental impact of an action (such as a transportation project) when added to other past, present, and reasonably foreseeable future actions.
Deadhead		A empty transit vehicle commute to or from a garage, terminal, or a destination between routes.
Decision-Support System	DSS	Computer assessment tool that examines the relationships between land use and transportation.
Deflection		A horizontal change in the travel path of traffic due to a physical feature of a roadway. An example would be a "Splitter Island" of a roundabout. Here traffic is slowed by a geometric curvature (or deflection) from a straight trajectory before entering a channelized approach into the roundabout.
Demand Response	DR	A transit mode comprised of passenger cars, vans, or small buses operating in response to calls from passengers or their agents to the transit operator, who then dispatches a vehicle to pick up the passengers and transport them to their destinations. A demand response (DR) operation is characterized by the following; 1. Vehicles do not operate over a fixed route or on a fixed schedule except on a temporary basis to satisfy a special need, 2. Vehicles may be dispatched to pick up several passengers at different pick-up points before taking them to their respective destinations and may even be interrupted en route to these destinations to pick up other passengers.
Demand Response Service		Shared use transit service operating in response to calls from passengers or their agents to the transit operator, who schedules a vehicle to pick up the passengers to transport them to their destinations.
Department of Public Works	DPW	Municipal entity responsible for repair and maintenance of streets, sewers, greenspace, and urban landscape. DPWs also designs and manage the construction of public facilities.
Department of Transportation	DOT	State agency responsible for coordination, operation, and safety of transportation facilities and services, including; highways, bridges, railroads, airports, etc.
Design Hour Volume	DHV	Commonly (but, not strictly) the 30th highest hourly traffic volume for a given year. DHV has been considered to be an optimal traffic volume estimation for designing future transportation infrastructure (e.g. intersection and roadway capacity analysis, bridge design, and geometric specifications, et al.) since the 1950 release of the Highway Capacity Manual (HCM).
Design-Build	D-B	Design-Build (D-B) is an efficient method to complete transportation projects, where designer engineers and construction contractors are brought together under a single contract. This contrasts to the traditional "Design-Bid-Build" (D-B-B) approach where two different contracting efforts must be undertaken in sequentially; 1. Obtaining engineering services on a negotiated-price basis, and 2. Obtaining construction services on the lowest-responsible-bid price basis.
Destination		The place or zone in which a trip terminates.
Destination Choice		An estimate of a trip endpoint determined by a combination of the purpose and origin of the trip. Destination choice is believed to depend on characteristics of the individual (income, auto ownership), characteristics and location of activities at which the trip’s purpose can be accomplished, and characteristics of transportation modes connecting the origin to each possible location.
Detectable Warning		Standardized surface feature built into pedestrian or transit-related infrastructure, which is designed to warn visually impared pedestrians of changes in curbline, slope, crossings, etc. It is generally a tactile standardized feature, intended to function much like a stop sign. It alerts perceivers to the presence of a hazard in the line of travel, whereupon they would stop, and determine the nature and extent of the hazard, before proceeding further.
Development Review Board	DRB	Development Review Boards are quasi-judicial, citizen volunteer bodies created under Vermont Statute 24 VSA Chapter 117, intended to interpret and uphold zoning ordinances of their municipality.
Diesel Multiple Unit	DMU	Self-propelled railcar, powered by one or more diesel engines.
Discretionary Funds		Funds whose distribution is not automatic and not by formula but dependent on the decision of some agency or party.
District Transportation Administrator	DTA	Administrative supervisor of regional transportation services or infrastructure.
Double-Stack Railcars		Rail-freight configuration allowing double-stacking of shipping containers-on-flat-cars (COFC) during transport. Operation of such a configuration can be hindered by clearance restrictions on rail lines.
Drayage		A carrier service (or charge) for the cartage of shipping containers from a dock to an intermediate or final destination.
Dynamic Striping		A traffic calming technique using experimental systems of pavement markings, which is not yet mandated by the Manual on Uniform Traffic Control Devices (MUTCD).
Earmark		A congressional budgetary mechanism built into the appropriation bill, often used to undertake specific projects. Earmarks are generally designated as a dollar amount.
Eastern Border Transportation Coalition	EBTC	Organization providing a cross-border issue forum for each U.S. state, Canadian province, and border service agency.
Egress		A way of exiting or travelling away from a location. Egress generally describes vehicle or pedestrian movements from the perspective of driveways and walkways which provide "egress from a property". See also "Access" or "Ingress".
Electronic Toll & Traffic Management	ETTM	ETTM systems equip vehicles with electronic tags (or transponders) that communicate with roadside sensors to provide automatic vehicle identification that allows for toll collection at the toll booth, and general vehicle monitoring and data gathering beyond the toll plaza. These systems the potential to reduce congestion, improve safety, energy efficiency, air quality, and to enhance economic productivity at a cost significantly less than additional road construction.
Emissions Budget		An aspect of the State Implementation Plan (SIP) that identifies allowable emissions levels, mandated by the National Ambient Air Quality Standards (NAAQS) for certain pollutants emitted from mobile, stationary, and area sources. The emissions levels are used for meeting emission reduction milestones, attainment, or maintenance demonstrations.
Emissions Inventory		An emissions inventory is a database that lists (by source of emission) the amount of air pollutants discharged into the atmosphere of a community or region during a given period of time.
Environmental Assessment	EA	The purpose of an EA is to determine if there is sufficient evidence for a proposed project to require a more comprehensive Environmental Impact Study (EIS). Often an EA is a sufficient environmental document in itself when impacts of a project minor or can be mitigated.
Environmental Impact Statement	EIS	Document that studies all likely impacts resulting from major federally-assisted programs. Impacts include those on the natural environment, economy, society, and the built (existing) environment of historical and aesthetic significance.
Environmental Justice	EJ	The fair treatment of people of all races, cultures, and income with respect to the development, implementation, and enforcement of environmental laws, regulations, programs and policies.
Environmental Protection Agency	EPA	The federal regulatory agency responsible for administering and enforcing environmental laws, including the Clean Air Act.
Equivalent Single Axle Load	ESAL	Equivalent 18-kip Single Axle Load. A basic premise of truck weight enforcement is that there is a resulting reduction in the rate of pavement deterioration. ESAL measures Truck traffic loading expressed as the number of equivalent 18,000 lb (80 kN) single axle loads.
Essential Air Services	EAS	Federal subsidy program for scheduled air services to rural communities
Excursion Train		A rail enterprise catering to tourism or leisure markets in the form of seasonal, recreational, historical, or tourist service destinations.
Expressway		A controlled access, divided arterial highway for through traffic where intersecting roads are bypassed via Grade Separation.
Fatality Analysis Reporting System	FARS	FARS is a federal census of crashes involving any motor vehicle on a trafficway, but only in fatal crashes. It is generally considered to be the most reliable national crash database. A large truck is defined in the FARS as a truck with a gross vehicle weight rating (GVWR) of more than 10,000 pounds. A bus is defined in the FARS as a large motor vehicle used to carry more than 10 passengers, including school buses, inter-city buses, and transit buses. FARS is maintained by the National Highway Traffic Safety Administration (NHTSA).
Federal Aviation Administration	FAA	U.S. Department of Transportation agency responsible for aviation related programs.
Federal Highway Administration	FHWA	U.S. Department of Transportation agency responsible for highways.
Federal Railroad Administration	FRA	U.S. Department of Transportation agency responsible for railroad programs.
Federal Transit Administration	FTA	U.S. Department of Transportation agency that administers federal funding to support a variety of locally planned, constructed, and operated public transportation systems throughout the U.S., including buses, subways, light rail, commuter rail, streetcars, monorail, passenger ferry boats, inclined railways, and people movers.
Federal-Aid Highway		Defined in 23 United States Code 101(a) as highways on the Federal-aid highway systems and all other public roads not classified as local roads or rural minor collectors. In the context of "Functional Classification", highways on the Federal-Aid System consist of; 1. A road in an Urban area that is at least an "Urban Collector" or higher (Functional Classes 1, 2, 6, & 7). 2. A road in a Rural area that is at least a “Rural Major Collector” or higher (Functional Classes 11, 12, 14, 16, & 17). Highways not on the Federal-Aid System consist of; "Urban Local Access", "Rural Minor Collector", & "Rural Local Access" (Functional Classes 19, 8, & 9 respectively).
Federal-Aid Interstate	FAI	Originally authorized by the Federal-Aid Highway Act of 1956, a system for the allocation of funds by formula was developed for Interstates, which was based the most heavily travelled routes of the Federal-Aid Primary system. The Federal-Aid Highway Act of 1973, which required the use of "Functional Highway Classification" to update and modify the Federal-aid highway systems by July 1, 1976 replaced this classification scheme.
Federal-Aid Primary	FAP	Originally authorized by the Federal-Aid Highway Act of 1944, a system for the allocation of funds by formula was developed based on area, population, and route miles. The Federal-Aid Primary system was considered the primary travelled roads. The Federal-Aid Highway Act of 1973, which required the use of "Functional Highway Classification" to update and modify the Federal-aid highway systems by July 1, 1976 replaced this classification scheme.
Federal-Aid Secondary	FAS	Originally authorized by the Federal-Aid Highway Act of 1944, a system for the allocation of funds by formula was developed based on area, population, and route miles. The Federal-Aid Secondary system was considered the "Farm-to-Market" roads. The Federal-Aid Highway Act of 1973, which required the use of "Functional Highway Classification" to update and modify the Federal-aid highway systems by July 1, 1976 replaced this classification scheme.
Federal-Aid System	FAS	Defined in 23 United States Code 101(a) as highways on the Federal-aid highway systems and all other public roads not classified as local roads or rural minor collectors. In the context of "Functional Classification", highways on the Federal-Aid System consist of; 1. A road in an Urban area that is at least an "Urban Collector" or higher (Functional Classes 1, 2, 6, & 7). 2. A road in a Rural area that is at least a “Rural Major Collector” or higher (Functional Classes 11, 12, 14, 16, & 17). Highways not on the Federal-Aid System consist of; "Urban Local Access", "Rural Minor Collector", & "Rural Local Access" (Functional Classes 19, 8, & 9 respectively).
Federal-Aid Urban	FAU	Those roads within Urbanized Areas (UA) that are designated upon the Federal-Aid System (FAS), and are functionally classed as; 11 (Urban Interstate), 12 (Urban Other Freeway or Expressway), 14 (Urban Other Principal Arterial), 16 (Urban Minor Arterial), or 17 (Urban Collector).
Feeder Service		Local transport providing passengers with connections to a longer service.
Finding of No Significant Impact	FONSI	If a "Finding of No Significant Impact" is concluded from an Environmental Assessment, a full EIS would not be required for the project.
Fiscal Year	FY	The Fiscal Year for the State of Vermont and the CCMPO is July 1 – June 30, while the TIP and STIP follow the Federal Fiscal Year (FFY) of October 1 – September 30.
Fixed Guideway	FG	A public transportation facility, which utilizes and occupies a separate right-of-way (ROW), or rail line, for the exclusive use of mass transportation and other high occupancy vehicles, or uses a fixed catenary system and a right of way usable by other forms of transportation. This term may include modes such as; rapid rail, light rail, commuter rail, automated guideway transit, people movers, ferry boat service, and fixed-guideway facilities for buses (such as bus rapid transit - BRT) and other high occupancy vehicles.
Fixed-Based Operator	FBO	Provider of aviation support services at airports, such as; fueling, line, paint, avionics, aircraft maintenance, hangar, catering, and other ground and/or logistical services.
Flexible Funds		Federal transportation funding that may be used for highway and/or transit.
Flood Zone A		Areas of a 100-year flood (1% chance flooding in a year). Such data represents a starting-point for floodplain mapping and should be used with caution as it may be highly inaccurate in some locations. Site-specific determinations should be done using the official source Flood Insurance Rate Maps (FIRMs), site inspections, interviews of people who witnessed historic floods, and if needed, hydrologic engineering studies.
Flood Zone B		Areas between a 100-year and 500-year flood (0.2% chance flooding in a year). Such data represents a starting-point for floodplain mapping and should be used with caution as it may be highly inaccurate in some locations. Site-specific determinations should be done using the official source Flood Insurance Rate Maps (FIRMs), site inspections, interviews of people who witnessed historic floods, and if needed, hydrologic engineering studies.
Floodplain		The National Flood Insurance Program (NFIP) regulates any development in mapped floodplains based on the 100-year flood (i.e. those areas which have a 1% chance of a flood in any given year). Federal Emergency Management Agency (FEMA) issued Flood maps delineate 100-year floodplains, as well as 500-year floodplains (i.e. those areas which have a 0.2% chance of a flood in any given year).
Fog Line	FOGL	Reflective white lines painted along the shoulder of a road demarking the legally extent a motor vehicle is allowed to operate.
Formula Grants		Funds distributed according to some legislated or regulated scheme.
Forty-Foot Equivalent Unit	FEU	A Forty-Foot Equivalent Unit is used to express shipping or capacity volume of freight. Using the ISO standard of double the 20-foot shipping container (i.e. TEU - Twenty-Foot Equivalent Unit) as a means of measurement, FEUs further summarise a general sense of freight traffic moving through major shipping ports commonly reported by government or industry. A FEU is an approximate measure of two containerized cargo units (20 ft. long * 8 ft. wide container), which does not account for container height. An FEU is generally the amount of freight carried by a standard 18-wheel tractor-trailer hauling a 48' trailer.
Freeway		A divided arterial highway designed for unimpeded flow of large traffic volumes, have controlled access, and grade separation from intersecting roads.
Freight Analysis Framework	FAF	Federal freight transportation data integration project, obtaining data from various sources to estimate and forecast freight activity among states, regions, and major international gateways.
Fringe Parking		Refers to any designated parking facility located outside a Central Business District (CBD) or other commercial activity center.
Frontage Road		A road abutting a limited-access highway that provides a means of access between the highway and local roads.
FTA Section 5307		Grant program for capital and operating assistance in urban areas with populations greater than 50,000.
FTA Section 5309		Grant for capital programs such as buses and bus facilities.
FTA Section 5310		Grant program to states for assisting private non-profit groups in meeting the transportation needs of the elderly and persons with disabilities.
FTA Section 5317		New Freedom Program. Grant program to encourage services and facility improvements to address the transportation needs of persons with disabilities that go beyond those required by the ADA.
Full Truck Load Carrier	FTL	Full truckload carriers usually haul freight in single moves from shipper to receiver. "For-hire TL carriers" haul freight and special commodities in full truckload quantities, often in long-hauls (less than 500 miles up to a “transcontinental” haul) on irregular schedules determined by demand of shippers and receivers. "Private TL carriers" haul special commodities in truckload quantities, usually between manufacturing plants and warehouses as an in-house service.
Functional Classification	FC	A Federal Highway Administration road designation scheme for rural, small urban, and urbanized areas. Functional classification defines the role that any particular road or street should play in servicing the flow of trips through a highway network. Standards for highway classification were developed during 1969-1971 using criteria and procedures specified in the 1968 National Highway Functional Classification Study Manual. The scheme may be expressed as: 1 = Rural Interstate, 2 = Rural Principle Arterial, 6 = Rural Minor Arterial, 7 = Rural Major Collector, 8 = Rural Minor Collector, 9 = Rural Local Access, 11 = Urban Interstate, 12 = Urban Other Freeway or Expressway, 14 = Urban Other Principal Arterial, 16 = Urban Minor Arterial, 17 = Urban Collector, 19 = Urban Local Access.
Gateway		Refering to a transportation or shipping corridor of national or international importance.
Geographic Information Systems	GIS	A software system which assists in the development, storage, analysis, and display of locational or spatial information.
Geographic Information Systems for Transportation	GIS-T	Refers to the principles and applications of applying geographic information technologies to transportation problems (Miller and Shaw, 2001).
Geotextiles		Synthetic polyethylene, polypropylene, polyester, or polyamide manufactured into fabrics in a woven or non-woven pattern to form a blanket-like product, which is used to stabilize soft sections on a gravel road.
Girder		A main horizontal support beam for a bridge structure that usually handles loads from smaller floor beams and stringers.
Global Climate Change	GCC	Global Climate Change
Global Positioning System	GPS	A navigation system utilising satellites to provide a GPS-receiver on Earth with accurate coordinates.
Grade Crossing		Where a roadway intersects a rail line.
Grade Separation		The raising or lowering of a roadway to bridge over another roadway, thereby eliminating traffic conflict.
Grant Anticipation Revenue Vehicles (Bonds)	GARVEE	GARVEE Bonds are funding mechanisms that enable governmental entities to finance infrastructure or transit projects based on anticipated future revenues, which are then used to repay outstanding debt. A state may use future federal-aid funding obligations to reimburse the retirement of principal loans, interest charges, issuance, insurance, and other associated costs related to the sale of eligible debt-financing instruments.
Gravity Model		An underlying premise of Travel Demand Forecasting/Modelling, based on Sir Issac Netwon's "Law of Universal Gravitation". Newton's gravity model was converted into a geographical context by W.J. Reilly in 1933. This theory is still known today as "Reilly's Law". This law has two concepts: 1. That a city attracts most of its commuters from the closest towns. 2. That a larger city attracts larger numbers of commuters than a smaller city. "A city will attract retail trade from a town in its surrounding territory, in direct proportion to the population size of the city and inverse proportion to the square of the distance from the city." (Reilly, 1929).
Green Book		Published by AASHTO, the "Green Book" is formally known as "A Policy on Geometric Design of Highways and Streets". It covers the latest geometric design practices in standard use for highways, intersections, and interchanges.
Greenhouse Gases	GHG	Identified by the Intergovernmental Panel on Climate Change (IPCC), anthropogenic greenhouse gases are recognized by the international scientific community as having the potential to bring about climate change. Such gases include; Carbon Dioxide (CO2), Methane (CH4), Nitrous Oxide (NOX), Carbon Tetrafluoride, Hexafluoromethanem, Sulfur Hexafluoride, and others.
Gross Domestic Product	GDP	GDP is a statistic estimating total market value of goods and services produced by labor and property in a given geographical area, within a given year. GDP replaces the Gross National Product (GNP) indicator as the primary measure of U.S. production in 1991.
Gross Vehicle Weight	GVW	Gross Vehicle Weight
Growth Center		Land Use term defined by Vermont staute as an area of land that incorporates a mix of uses that typically or potentially include uses such as; retail, office, commercial, civic, recreational, industrial, and residential within a densely developed, compact area that promotes social interaction. Growth centers are located in or adjacent to a designated downtowns, village centers, or new town centers with clearly defined boundaries that have been approved by one or more municipalities in their municipal plans to accommodate a majority of growth anticipated over a 20-year period.
Hazardous Material	HAZMAT	Classified by the U.S. Environmental Protection Agency (EPA), transport of HAZMAT is regulated by the U.S. Department of Transportation.
Headway		Often used in context of transit service, "Headway" refers to the time interval between buses or passenger trains moving towards a specific destination or transit-stop along a particular route.
Heavy Rail		Rapid rail transit service using rail cars powered by electricity drawn from a third rail and usually operated on exclusive rights-of-way. It usually uses longer trains and has longer spacing between stations than light rail. (For example, the New York City subway system).
High Accident Location	HAL	A location on the federal-aid highway system that has experienced a minimum of five accidents over a five-year period and has an Actual Rate to Critical Rate Ratio (ARCR) of 1 or greater. The list of HALs is maintained by the Vermont Agency of Transportation - Highway Research Section.
High Occupancy Vehicle	HOV	Vehicle carrying two or more people (i.e. a carpool). Roads may have lanes solely for HOV use, such as carpools, vanpools, and buses.
High Risk Rural Roads Program	HRRR	A federal safety and funding provision addressing the high fatality and incapacitating injury rate, which occurs on rural roads (nationally, about 60% occur on Rural Major & Minor Collectors, as well as Rural Local Access roads).
High Speed Rail	HSR	Intercity passenger rail service that is reasonably expected to reach speeds of at least 110 miles per hour (49 U.S.C. §26105 (b)(4)).
Highway Capacity Manual	HCM	Published by the Transportation Research Board (TRB), the HCM outlines fundamental information and computational techniques on the quality of service and capacity of highway facilities.
Highway Performance Monitoring System	HPMS	A GIS-based national highway information system that includes data on the extent, condition, performance, use, and operating characteristics of US highways.
Highway Safety Improvement Program	HSIP	Federal program assisting states to achieve a significant reduction in traffic fatalities and serious injuries on all public roads through the implementation of infrastructure-related highway safety improvements.
Highway Trust Fund	HTF	A financing mechanism established under federal law to account for tax receipts (primarily from motor fuel taxes) collected by the federal government and dedicated to surface transportation projects.
Home-Based Trip		A trip that starts and/or ends at home.
Home-Based Work Trip		A trip with one end at work and the other at home.
Hot Spot		A location with higher-than-ambient levels of pollution. Hot spots may be attributed to such things as weather patterns, topography, and traffic intensity.
Hydrocarbons	HC	Hydrocarbons are a Volatile Organic Compound (VOC) that is released into the atmosphere because of incomplete combustion of petroleum fuels or by their evaporation. The strong odor of diesel fuel is associated with HC. The EPA states that 47% of Hydrocarbon emissions in our atmosphere can be attributed to vehicles. Hydrocarbons combined with Nitrogen Oxides, and sunlight form Ozone (O3).
I-95 Corridor Coalition		The I-95 Corridor Coalition is an alliance of transportation agencies, toll authorities, and related organizations, including public safety, from the State of Maine to the State of Florida, with affiliate members in Canada. The Coalition provides a forum for key decision and policy makers to address transportation management and operations issues of common interest. This volunteer, consensus-driven organization enables its myriad state, local and regional member agencies to work together to improve transportation system performance far more than they could working individually. The Coalition has successfully served as a model for multi-state/jurisdictional interagency cooperation and coordination for over a decade. Vermont is considered to be a part of the I-95 region.
Impact Fee		A local government imposed fee upon developers, which in theory is used to finance infrastructure costs and improvements that handle increased service caused by new development.
Indirect Impacts		Impacts that are caused by an action (such as a transportation project) that occur later in time and farther removed in distance, but are still foreseeable. Also known as "Secondary Impacts."
Induced Travel		Formally known as the "Traffic Inducement Effect", it is a highly debated concept in transportation planning, which postulates that improvements intended to increase highway capacity are only a temporary solution. Simply stated, Induced Travel is any increase in daily travel (measured as Passenger Miles of Travel [PMT] or Vehicle Miles of Travel [VMT]) resulting from a change in the transportation system.
Ingress		A way of entering or travelling to a location. Ingress generally describes vehicle or pedestrian movements from the perspective of driveways and walkways which provide "ingress to a property", or more commonly "Ingress & Egress to a property" or "Access & Egress to a property".
Innovative Finance	IF	A broadly defined term that encompasses a combination of specially designed techniques to supplement traditional federal financing methods for transportation-related projects. Often in the form of "Public-Private Partnerships", locally authorized "Tax-Increment Financing", et al., Innovative Finance for transportation seeks to; 1. Maximize the ability of states and other project sponsors to leverage Federal capital for needed investment in the nation's transportation system; 2. More effectively utilize existing funds; 3. Move projects into construction more quickly than under traditional financing mechanisms; and 4. Make possible major transportation investments that might not otherwise receive financing.
Inscribed Circle Diameter	ICD	Diameter of a Rotary, Roundabout, or Circulator intersection. Generally speaking, a smaller ICD of a modern roundabout keeps the traffic speed lower, and hence safer than the larger ICD's commonly found with rotaries or traffic circles.
Intelligent Transportation Systems	ITS	Technology used to improve the efficiency of transportation systems.
Intercept Facility		Otherwise known as a "Satellite Facility", an Intercept "Park & Ride" facility's purpose is to provide a less expensive parking alternative to on-site locations within activity centers or the urban core area and reduce SOV use in activity centers. These facilities may capture outgoing as well as incoming activity center traffic and serve as a transfer point from car to shuttle or transit. Characteristics include an urban/activity area fringe location, high capacity, surface or structured parking, and high frequency shuttle/transit connections to activity centers. Implementation funding is likely to come from Congressional earmarks and/or public private ventures.
Intermodal		Planning that reflects a focus on connectivity between modes and emphasizes choices, coordination, and cooperation.
Intermodal Surface Transportation Efficiency Act of 1991	ISTEA	The purpose of this act was to develop a 'National Intermodal Transportation System that is economically efficient, environmentally sound, provides the foundation for the Nation to compete in the global economy and will move people and goods in an energy efficient manner.' This act established the provision that MPO's undertake development of a Transportation Improvement Program (TIP), a long-range plan, and an annual work program. It also required for states; a statewide planning process, a statewide transportation plan, and a statewide transportation improvement program (STIP).
Intermodal Transfer Facility		Involves moving containers between rail and truck, or other modal combinations, and can increase efficient transportation services and energy efficiency because a train loaded with containers can carry the same load as dozens of trucks. Such service can contribute to reduced truck traffic on congested highways, reduced damage to highways from heavy trucks, and improved air quality.
International Organization for Standardization	ISO	Based in Geneva, Switzerland, ISO is a non-governmental organization (NGO) coordinating the publication and development of a host of International Standards for government, private-sectors. Such standards apply to equipment specifications, data transfer standards, monitoring standards, et al. The acronym "ISO" is derived from the Greek 'isos' (meaning "equal"). Hence "ISO" is applicable to any country or language as a mark of an international standard.
International Roughness Index	IRI	A pavement condition profiling indicator (used by HPMS, et al.) reflecting ride smoothness. IRI data is captured by a device mounted on a vehicle measuring suspension motion per distance travelled, and may be expressed in inches/mile (in/mi) or meters/kilometer (m/km). An IRI of 0m/km means that a roadway is perfectly smooth. And where there is no maximum for this indicator, it is generally accepted that an IRI of 8m/km is almost impassible unless vehicle speeds are greatly reduced.
Intersection Sight Distance	ISD	The AASHTO "Green Book" reference to the "Line of Sight" distance between a vehicle travelling on a roadway and a vehicle attempting to enter the roadway from an intersection or driveway.
Interstate Highway System	IHS	A subsystem of the NHS, the Interstate Highway System is also named the "Dwight D. Eisenhower National System of Interstate and Defense Highways". The concept of the IHS was first formally studied under mandate by the Federal-Aid Highway Act of 1938, and was first authorized construction funds under the Federal-Aid Highway Act of 1952. It was not until the enactment of the Federal-Aid Highway Act of 1956, championed by President Eisenhower, that the Highway Trust Fund was established to finance construction of the entire network for the purpose of facilitating private and commercial transportation, and providing transportation routes for military supplies and troop deployments in case of an emergency or foreign invasion.
Interstate Maintenance Program		Federal program providing funding for resurfacing, restoring, rehabilitating and reconstructing (4R) most routes on the Interstate Highway System.
Jake Brake		Engine-induced braking system on trucks, often associated with noise issues in local neighborhoods.
Job Access/Reverse Commute	JARC	Transit improvement plan designed to meet the work-related transportation needs of low-income residents.
Joint Use		Parking lots that allow for commuter parking, which is normally utilised for a different purpose, such as; Shopping centers, Government, or Recreation.
Journey-To-Work Data	JTW	Worker/Commuter home-based work trip sample data collected by the U.S. Census Bureau within the long form since 1960.
Just-In-Time-Delivery	JIT	A method of inventory control where products are delivered to stores or assembly lines only when needed to minimize the high cost of maintaining local inventory and warehousing. The effects on freight demand are to; increase the number of individual shipments, decrease their length of haul and costs, and increase the reliability of on-time delivery.
Key Station Plan		A document designating critical transit facilities needed to expand accessibility for individuals with disabilities and to meet the Americans with Disabilities Act (ADA) requirements.
Kiosk		In the context of Transportation, kiosks are interactive systems set up in airports, transit terminals, or commercial activity centers to assist travelers with transportation or other logistical information.
Kip		A unit equalling 1000 pounds of force upon a surface (i.e. "kilopound"). In transportation, it is used to describe the load bearing wear upon a roadway. Often expressed as a component of an indicator of truck wear upon a road surface, it is expressed as "Equivalent Single Axle Load" (ESAL), which is comprised of 18 kip, or 18,000 lbs. per axle on a truck.
Kiss and Ride		Area where commuters are driven and dropped off to take a public transportation service.
Land Use		The purpose for which land or the structures on the land are being utilized (e.g., commercial, residential, or retail). Also used as a description of activities found throughout an urban area.
Land Use Allocation Module	LUAM	The Land Use Allocation Module (LUAM) has been used by CCMPO & CCRPC to forecast future land use patterns. The primary data inputs are; housing & employment by type of Traffic Analysis Zone (TAZ) in the model, physical constrains data, and zoning data.
Land-Based Classification Standards	LBCS	American Planning Association (APA) standardised model used to categorise land use based on its charcteristics. Such characteristics are defined as; Activity, Function, Structure, Site Development Character, and Ownership Type.
Lane Miles		Road centerline miles multiplied by the number of lanes. Hence, a four-lane road that is 5 miles long is 20 Lane Miles.
Less-Than-Container-Load	LCL	Refering to "Containers" or ISO multimodal shipping Containers; Less-Than-Container-Load.
Less-Than-Truckload Carrier	LTL	LTL carriers haul general freight in less than a full truckload quantity, often in a short-haul or regional move. "For-hire" LTL's often combine freight from multiple shippers and operate local pickup and delivery service in urban areas on regular routes (known as line-haul relays, or terminal to terminal service). "Private" LTL's typically handle short-haul moves between warehouses and retailers as an in-house service.
Level of Service	LOS	A system of indicating delay at signalized intersections, which is graded on a letter scale from A to F, generally outlined by the HCM as: A <= 10 sec, B = 10-20 sec, C = 20-35 sec, D = 35-55 sec, E = 55-80 sec, F > 80sec.
Light Duty Vehicle	LDV	Passenger cars, pick-up trucks, vans, or light-duty trucks with a gross vehicle weight rating of 8,500 lbs. or less, plus an adjusted loaded vehicle weight of 5,751 lbs. or less
Light Rail Transit	LRT	Generally applies to single- or double-car rail transport that uses mostly mixed, but not usually grade-separated, rights-of-way. LRT is an intermediate-capacity, intermediate-speed mode with service capabilities between heavy rail transit and local bus. Other forms and terms of LRT include; electric trolleys, streetcars, or tramways.
Limited Access Highway		A highway intended for free-flow traffic, which has a limited number of interchanges.
Line Haul Service		Transport along a single corridor without branches.
Line of Sight Distance		The unobstructed view from an intersection down an intersecting roadway. Sufficient line of sight allows for enough driver reaction time and vehicle movement to avoid collisions during turning movements (Also see Intersection Sight Distance).
Linear Reference System	LRS	A major component of the Highway Performance Monitoring System (HPMS) program that assigns a separate link and node GIS database for all National Highway System (NHS) Routes, Rural & Urban Principal Arterial roads, and Rural Minor Arterial roads.
Link		An element of a transportation network that represents a segment which terminates in a node at the other end. A link may have a number of attributes, including distances, number of lanes, capacity, and direction, and is often assigned a travel time function to the volume of traffic using the link.
Liquefied Natural Gas	LNG	A natural gas fuel comprised mainly of methane, cooled to below its boiling point of -260 degrees Fahrenheit, where it becomes a liquid. LNG is stored at very low temperatures within a special low-pressurized vacuum container. LNG does not burn in liquid form.
Local Emergency Planning Committee	LEPC	A committee under the Chittenden County Regional Planning Commission (CCRPC), LEPC function is to provide resources and guidance to Chittenden County communities through education, coordination and assistance in hazmat planning, as well as to assure public health and safety.
Local Enhancements		Otherwise known as "Local Tranportation Facilities", it is the State program administering development of Enhancement Projects, Bicycle and Pedestrian Facilities, Safe Routes to School Projects, Park-n-Rides, Scenic Byways and "Local" Projects. The majority of the projects have a high degree of local focus and for the most part, development and construction is managed by local municipalities.
Local Service		Transit service involving many stops and low operating speeds with the purpose of picking up or delivering passengers as closely as possible to origins and destinations.
Local Street		Street designed to provide access to and from homes and businesses.
Local Transportation Assistance Program	LTAP	Federally funded program to enable local governments to improve their roads and bridges by providing training and information.
Local Transportation Facilities	LTF	Also known as "Local Enhancements", LTF is a Vermont Agency of Transportation (VTrans) program established to assist local governments with project implementation for; Bicycle and Pedestrian Facilities, Safe Routes to School Projects, Park-n-Rides, Scenic Byways and other "Local" Projects.
Long Range Transportation Plan	LRTP	A long-range document required by federal law that identifies facilities and programs that should function as an integrated metropolitan transportation system and includes a financial plan that demonstrates how the long-range plan can be implemented. Federal requirement for MPOs and Agencies of Transportation to undertake every five years and looks out 20-25 years.
Longer Combination Vehicles	LCV	Vehicles with two or more trailer units that have gross weights of more than 80,000 pounds. LCVs typically include four vehicle types: 1. "ROCKY MOUNTAIN DOUBLE" - (105,000 lbs./Len. 95'/3 Trailers: 1 = 48', 2 = 28'), 2. "TURNPIKE DOUBLE" - (Wt. 135,000 lbs./Len. 120'/2 Trailers of 48'), 3. "TRIPLE TRAILER" - (Wt. 110,000 lbs./Len. 110'/3 Trailers of 28'), 4. "STAA DOUBLE (WESTERN DOUBLE)" - (Wt. ?/Len. 65'/2 Trailers of 28').
Longitudinal Employer-Household Dynamics	LEHD	Longitudinal Employer-Household Dynamics (LEHD) is an innovative program within the U.S. Census Bureau using modern statistical and computing techniques to combine federal and state administrative data on employers and employees to derive their commuting patterns. The process generalizes datasets to protect the confidentiality of people and firms that provide information. This data is often useful in determining commuter-sheds in tandem with the Census Transportation Planning Package (CTPP).
Loop Detectors		Sensory equipment installed beneath the road surface that helps to monitor, collect data, and manage incidents of vehicle traffic.
Low Emission Vehicle	LEV	A vehicle certified to meet low emission standards set by the California Air Resources Board. These regulations are stricter than the US national "Tier" regulations.
Low Volume Road		According to the MUTCD (Section 5A.01), a low volume road is: "a facility lying outside of built-up areas of cities, towns, and communities, and it shall have a traffic volume of less than 400 AADT." According to the AASHTO "Green Book" (i.e. Guidelines for Geometric Design of Very Low-Volume Local Roads), a low volume road has an "ADT less than or equal to 400".
Magnetic Levitation	MAGLEV	High-Speed fixed-guideway transportation systems, which utilize magnetic levitation or suspension (which counteracts gravity) instead of conventional rail infrastructure.
Maintenance Area		Any U.S. region previously designated "Nonattainment" pursuant to the Clean Air Act Ammendments of 1990 (CAAA) and subsequently redesignated to "Attainment". Such regions are subject to develop a maintenance plan under section 175A of the Clean Air Act as ammended.
Manual on Uniform Traffic Control Devices	MUTCD	Published by Federal Highway Administration (FHWA), this manual defines the standards used by road managers nationwide to install and maintain traffic control devices (signage, pavement markings, traffic signals, etc.) on all streets and highways.
Maritime Administration	MARAD	The Maritime Administration is the agency within the U.S. Department of Transportation dealing with waterborne transportation. MARAD is responsible for waterborne transportation, the U.S. merchant marine, and other areas, such as; ships, shipping, shipbuilding, port operations, vessel operations, national security, environment, and safety.
Measures of Effectiveness	MOE	Indicators or test results reflecting degree of attainment for specific objectives.
Memorandum of Understanding	MOU	A document providing specific duties and responsibilities to be assumed by two or more parties in pursuit of a project or goal.
Metropolitan Planning Organization	MPO	Federally established organization responsible for a cooperative, continuous, and comprehensive framework to make transportation investment decisions within their designated area.
Metropolitan Statistical Area	MSA	Defined by the U.S. Office of Management and Budget, an MSA is a county or a group of contiguous counties that contain at least one city of 50,000 inhabitants or more, or 2) An urbanized area of at least 50,000 inhabitants and a total MSA population of at least 100,000 (75,000 in New England). The contiguous counties are included in an MSA if, according to certain criteria, they are essentially metropolitan in character and are socially and economically integrated with the central city. In New England, MSAs consist of towns and cities rather than counties.
Metropolitan Transportation Plan	MTP	A federally-mandated long-range plan for transportation development and investment based on the goals in the CCMPO Vision Statement.
Metropolitan Transportation System	MTS	The multimodal network of highways, arterial and collector roadways, transit services, rail lines, Burlington International Airport, and other intermodal facilities critical to the movement of people and goods in Chittenden County.
Milemarker	MM	A milemarker (i.e. milepost) is a reflective green paddle sign placed alongside highways indicating total mileage from an original control point. For Interstates, the zero milemarker originates at the southernmost, or the westernmost end of the route. However, for other routes, the location of the zero milemarker varies. The Vermont Agency of Transportation (VTrans) manages their milemarkers from South to North, and West to East. This is reflected in their distributed GIS data.
Milepost	MP	A milepost (i.e. milemarker) is a reflective green paddle sign placed alongside highways indicating total mileage from an original control point. For Interstates, the zero milepost originates at the southernmost, or the westernmost end of the route. However, for other routes, the location of the zero milepost varies. The Vermont Agency of Transportation (VTrans) manages their mileposts from South to North, and West to East. This is reflected in their distributed GIS data.
Minor Civil Division	MCD	A U.S. Census Bureau designated Minor Civil Division (MCD) is a legally specified (by State law) county governmental or administrative subdivision (e.g. township, gore, grant, unincorporated place, et al.). There states where MCDs do not exist. In such case the Census Bureau, in cooperation with state and local officials, delineates county subdivisions known as Census County Divisions (CCD). In some situations, the Census Bureau must complete the coverage of subcounty units by creating additional entities called unorganized territories (UTs) that it treats as being statistically equivalent to MCDs.
Mobile Source Pollutants		Vehicle-generated pollutants as regulated by the U.S. Environmental Protection Agency (EPA) for air quality. These include; Carbon Monoxide (CO), Hydrocarbons (HC) or Volatile Organic Compounds (VOCs), Nitrogen Oxides (NOx), Small Particulate Matter (PM-10), and Large Particulate Matter (PM 2.5).
Mobile6		A vehicle emission modelling software, which develops factors for predicting gram per mile emissions of Hydrocarbons (HC), Carbon Monoxide (CO), Nitrogen Oxides (NOx), Carbon Dioxide (CO2), Particulate Matter (PM), and toxics from mobile sources under various conditions. This model has been upgraded/replaced by a model called MOVES.
Mobility		The door-to-door experience of traveling or shipping goods throughout our communities and across the region, measured in terms of travel time, comfort, convenience, safety, and cost.
Mode		One of several major types of transportation such as rail, bus, automobile, and non-motorized (bicycle/pedestrian) transportation.
Mode Choice		A process by which an individual selects a transportation mode for use on a trip chain, given the trip’s purpose, origin, and destination; characteristics of the individual; and characteristics of travel by the realistically available modes.
Mode Split		The percentage, or share, of trips captured by the various transportation modes.
Model		In Transportation or Land-Use Planning, a computer model is employed to generate forecasts on future conditions of population levels, traffic, economic development, housing development, etc. Such a tool ought to be considered a Decision-Support system, augementing sound judgement of a decision-making entity.
Motor Vehicle Emission Simulator	MOVES	EPA's Office of Transportation and Air Quality (OTAQ) is developing the "MOtor Vehicle Emission Simulator" (MOVES). The successor to MOBILE6, this more recent emission modeling system estimates emissions for on-road and nonroad mobile sources, covers a broader range of pollutants, and allows multiple scale analysis from fine-scale analysis to national inventory estimation. MOVES is planned to serve as the replacement for MOBILE6 and NONROAD for all official analyses associated with regulatory development, compliance with statutory requirements, and national/regional inventory projections.
Multimodal		Using several integrated modes of transportation (rail or bus transit, carpool, bicycle, pedestrian, single-occupancy vehicle, etc.) in a given area.
National Ambient Air Quality Standards	NAAQS	Clean Air Act standards for widespread pollutants from numerous and diverse sources considered harmful to public health and the environment.
National Association of Development Organizations	NADO	Formed in 1967, NADO is an advocacy organization for federal programs and policies, which promote regional strategies and address local economic development needs.
National Association of Regional Councils	NARC	Formed in 1967, NARC is an advocacy organization serving as a national forum for regionalism. Member organizations are comprised of Metropolitan Planning Organizations (MPO), Regional Planning Agencies (RPA/RPC), Council of Governments (COG), etc., which work on transportation, community, economic development, and environmental quality issues.
National Cooperative Highway Research Program	NCHRP	A research program of the Transportation Research Board (TRB) that develops near-term, practical solutions to problems facing transportation planning agencies.
National Environmental Policy Act	NEPA	Federal law requiring federal agencies to integrate environmental values into their decision making processes by considering the environmental impacts of their proposed actions and reasonable alternatives to those actions.
National Highway Institute	NHI	NHI is the training and education arm of the Federal Highway Administration (FHWA), established by Congress in 1970.
National Highway System	NHS	As of 2008, the NHS is comprised of about 160,000 miles (256,000 kilometers) of roadway important to the nation's economy, defense, and mobility. The National Highway System (NHS) includes the Interstate Highway System as well as other roads important to the nation's economy, defense, and mobility. The NHS was developed by the Department of Transportation (DOT) in cooperation with the states, local officials, and metropolitan planning organizations (MPOs).
National Highway System Program	NHSP	The program provides funding for improvements to rural and urban roads that are part of the NHS, including the Interstate System and designated connections to major intermodal terminals. Under certain circumstances, NHS funds may also be used to fund transit improvements in NHS corridors.
National Highway Traffic Safety Administration	NHTSA	NHTSA was established in 1970 by the Highway Safety Act of 1970. Its mission is to; "Save lives, prevent injuries and reduce economic costs due to road traffic crashes, through education, research, safety standards and enforcement activity."
National Household Travel Survey	NHTS	The NHTS is national survey of daily and long-distance travel. The survey includes demographic characteristics of households, people, vehicles, and detailed information on daily and longer-distance travel for all purposes by all modes. Survey data are collected from a sample of U.S. households and expanded to provide national estimates of trips and miles by travel mode, trip purpose, and a host of household characteristics. NHTS updates information gathered by two series of travel surveys—the Nationwide Personal Transportation Survey (NPTS) conducted in 1969, 1977, 1983, 1990, and 1995 and the American Travel Survey (ATS) (covering U.S. Long-distance travel information), which was conducted in 1977 and 1995. The 2001-2002 NHTS combines questions about daily and long-distance trip-making characteristics in one survey. The seventh series of NHTS was undertaken in 2008-2009 to include approximately 150,000 households across the nation.
Natural Gas Vehicle	NGV	NGV's use Compressed Natural Gas (CNG)- composed of Methane, or a less common Liquefied Natural Gas (LNG) as a cleaner alternative to petroleum-based fossil fuels.
Network		In planning, a network is a computerized representation (often times in the for of a GIS or other digital model) of roadways and intersections that describes a transportation system. For highway engineering, a network is a configuration of highways that constitutes the total system. In transit operations (bus, passenger rail, et al.), a network is a system of transit lines or routes, usually designed for coordinated operation.
New England Central Railroad	NECR	A privately operated railroad company.
New Starts		The "Federal Transit Act" authorized temporary discretionary funds intended help start new fixed-route transit systems or services.
Nitrogren Oxides	NOX	Precursor emission that forms from high-temperature combustion processes. React with VOCs in the presence of heat and sunlight to form ozone.
Node		A point where two links join a network, usually representing a decision point for route choice but sometimes indicating only a change in some important link attribute.
Nonattainment Area		A geographic area that in the US EPA has designated as not meeting the NAAQS. The Chittenden County area has not been designated as a nonattainment area for ozone or CO at this time.
Nonmotorized Transportation Pilot Program	NTPP	SAFEATEA-LU Section 1807 established the NTPP. This program is providing 25 million dollars each to four communities--Columbia, MO; Marin County, CA; Minneapolis Area, MN; Sheboygan County, WI--to demonstrate how improved walking and bicycling networks can increase rates of walking and bicycling.
Notice of Intent	NOI	A notice informing the public that an Environmental Impact Statement will be undertaken for a project.
Off Peak		Trips that occur during period of relatively low traffic.
Official Business Directional Sign	OBDS	An official Vermont Agency of Transportation designated business directional sign, which includes a legal business name, logo, directional arrow, and mileage from the business. Black OBDS signs indicate businesses, where brown OBDS signs represent recreational areas (brown signs requiring FHWA approval to use). Towns are assessed an installation fee and an annual maintenance fee for each sign.
Offtracking		The tendency for rear tires to follow a shorter path than the front tires when turning. This is a primary concern with Trucks, Buses, or trailered vehicles because rear tires may clip street signs, or drive onto shoulders, walkways, or bike lanes, or cross the centerline on a curve, creating a safety hazard for adjacent and oncoming traffic.
Origin		The location or zone at which a trip begins; the place where a trip is “produced.”
Origin/Destination Study	O-D	A study of where person or vehicle trips begin and end. Such a study may also include trip purposes and frequencies.
Ozone	O3	A colorless gas with a sweet odor that is not a direct emission from transportation sources, but is formed when VOCs and NOx from car exhausts and some industrial emissions combine in the presence of sunlight. Ground-level ozone is associated with smog conditions and initiates damage to lungs, trees, crops and materials. Requlated by the Clean Air Act Amendments of 1990 (CAAA).
Paratransit		Flexibly-scheduled transportation services catering to special needs populations such as the elderly and disabled.
Park & Ride Facility	P&R	A parking lot designated by the state or a municipality for the purpose of commuter travel, allowing for a mode shift from automobile to transit or carpool. According to the 2004 CCMPO Park & Ride Prioritization Plan, there is a distinction between an "Intercept" (or "Satellite") lot and a "Park & Ride" lot. A Park & Ride lot's purpose is for car and vanpooling with potential for low frequency shuttle or transit service. It may serve multiple trip destinations. It is characterized by its suburban or rural location, a surface lot (v.s. parking structure), and low to medium capacity. The private car is the dominant method of trip collection and distribution. These facilities are implemented through public funding. The purpose of an "Intercept Lot" is to provide a less expensive parking alternative to on-site locations within activity centers or the urban core area and reduce SOV use in activity centers. These facilities may capture outgoing as well as incoming activity center traffic and serve as a transfer point from car to shuttle or transit. Characteristics include an urban/activity area fringe location, high capacity, surface or structured parking, and high frequency shuttle/transit connections to activity centers. Implementation funding is likely to come from Congressional earmarks and/or public private ventures.
Parking Accumulation		Total number of vehicles parked within a parking facility at a given time, usually during peak use.
Partial Zero Emission Vehicle	PZEV	A vehicle that has zero evaporative emissions from its fuel system, has a 15 year (or at least 150,000 mile) warranty, and meets SULEV tailpipe emission standards.
Particulate Matter	PM	An indicator used in the description of Air Quality assessment. PM is a term describing a mixture of solid particles and liquid droplets monitored in the air. PM originates from fuel combustion from automobiles, power plants, industrial facilities, and residential fireplaces and wood stoves. Fine particles (PM 2.5 = 2.5 microns or smaller) are closely associated with health effects, such as; increased hospital admissions and emergency room visits for heart and lung disease, increased respiratory symptoms and disease, decreased lung function, and premature death. Larger particles (PM10 = 2.5 - 10 microns) generally occur as smoke, dust, pollen, etc., which settle relatively quickly when compared to fine particles.
Parts per Million	PPM	A measure of air pollutant concentrations.
Passenger Car Equivalents	PCE	Traffic engineering/modelling practice of converting Trucks, Buses and RV's to cars for the purpose of Capacity or Level of Service (LOS) analyses. More information on this topic may be found in the Highway Capacity Manual (HCM).
Passenger Facility Charge	PFC	A surcharge added to the price of an airfare and used for capital improvements at airports.
Passenger Miles Traveled	PMT	1. AIR MODE: One passenger transported 1 mile; passenger-miles for one inter-airport flight are calculated by multiplying aircraft miles flow by the number of passengers carried on the flight. The total passenger-miles for all flights is the sum of passenger-miles for all inter-airport flights... 2. AUTO MODE: One passenger traveling 1 mile; e.g., one car transporting two passengers 4 miles results in 8 passenger-miles... 3. TRANSIT MODE: The total number of miles traveled by transit passengers; e.g., one bus transporting five passengers 3 miles results in 15 passenger-miles.
Pavement Condition Index	PCI	A rating from 0-100 (with a corresponding qualitative rating from 'Failed' to 'Good'), reflecting the condition or level of wear of pavement along a road segment.
Peak Hour Factor	PHF	PHF is used to evaluate roadway capacity. It is the ratio of of total hourly volume to the maximum 15 minute rate of flow within the hour, that is; PHF = Hourly Volume / Peak Rate of Vehicle Flow (within the hour).
Peak Oil		A term refering to the "Peak" of global petroleum production (i.e. location, extraction, and refinement of oil). Though it does not refer to petroleum depletion per se, it does consider the reduction of its finite reserves. "Peak-Oil" alludes to the ever more difficult means for extraction and supply of inexpensive oil to which the staus-quo global economy relies. It further considers the time when it requires the energy of one barrel to extract a barrel of oil.
Peak Period/Peak Hour		The time period (or specific hour) during which the roadway carries the greatest number of vehicles. Traffic impacts are typically evaluated during the morning and afternoon peak hours when the greatest numbers of motorists are traveling to and from work. It may be specified as the morning peak period (traditionally 7-9 AM) or evening (4-6 PM) peak.
Peak Spreading		A Travel Demand Forcasting modeling concept where there is a calculation of a time-of-day shift in the peak period (i.e. when the maximum amount of traffic occurs). Where many travel demand models use only PM peak hour data (anywhere from 4-6 PM), a peak-spreading travel demand model uses an entire day of data (e.g. a "Day-based model" as opposed to a "PM peak model") to calculate this figure.
Pedestrian Environmental Factor	PEF	In traffic modeling, the PEF identifies the pedestrian and bicycle-friendly parts of the transportation network.
Perception, Identification, Emotion, and Volition	PIEV	According to the Institute of Transportation Engineers (ITE), PIEV times range from 2.5 sec. for general warning signs to 14.5 sec. for signs requiring a high degree of judgment from the driver. PIEV Distance may be expressed as: dp = 1.47 × V × t, where dp = Perception-reaction distance in feet, V = Speed in miles per hour (mph), t = Perception-reaction time in seconds, and 1.47 is a factor to convert speed from miles per hour (mph) to feet per second (fps).
Perception-Reaction Time	PRT	PRT outlines four distinct processes a driver must perform for roadway navigation; Detection, Identification, Decision, & Response. Where PRT varies widely among drivers, AASHTO suggests it to be 2.5 seconds (where 90% of drivers will have a PRT as fast as, or faster than 2.5 seconds). ITE suggests it is 1.0 seconds (where 85% of drivers would have as an aspect of reacting to signal timing, but it would be considerably higher for a braking response upon a highway). Other factors that influence a PRT are; age, fatigue, complexity of reaction, and alcohol.
Person Trip		The movement of a person from an origin to a destination. A carpool carrying three people from origin-to-destination make one vehicle trip, its occupants together have made three person trips.
Personal Rapid Transit	PRT	An energy-efficient, on-demand, guided route, mass-transit system, utilizing small, independent vehicles (e.g. Podcars).
Piggyback Service		A rail and truck combination service where a shipper loads a truck trailer, a truck delivers it to a rail terminal where it is loaded on a flatcar. The railroad then hauls the Trailer-on-Flatcar (TOFC) to a destination terminal, where it is offloaded and trucked to the consignee.
Planning Funds	PL	Funds intended for planning purposes only. Such funds are intended to be exclusive of design or engineering of transporation projects, as well as operations or right-of-way acquisitions. Planning funds may however, be used for project scoping.
Portland Cement Concrete	PCC	Portland Cement Concrete is a durable, but complex substance commonly refered to as "concrete".
Preliminary Engineering	PE	Project development phase in which project design is determined.
Project Definition Team	PDT	Comprised of various VTrans department heads who review transportation projects.
Project Development Process	PD	Otherwise known as "Scoping", the Project Development life-cycle of a transportation project generally has several steps: 1. Local Concerns Meeting. 2. Data Collection. 3. Alternatives Development. 4. Alternatives Presentation Meeting. 5. Alternatives Selection. 6. Report Preparation. 7. Report Acceptance by the State DOT (i.e. VTrans) Project Definition Team (PDT).
Property Damage Only	PDO	A reportable crash, which does not result in any fatalities or noteworthy injuries.
Public-Private Partnerships	PPP	Contractual arrangements between government agencies and private-sector entities to finance transportation projects.
Quality Assurance Project Plan	QAPP	A QAPP documents the planning, implementation, assessment procedures, and quality control activities for any particular project. It integrates all the technical and quality aspects of the project in order to provide a blueprint for obtaining the type and quality of environmental data needed for a specific decision or use. All work performed or funded by EPA that involves the acquisition of environmental data must have an approved QAPP.
Queue		A line of waiting persons or vehicles. For example; a bottleneck of traffic at a signal, a line taxis at an airport, or people in line to board a bus or aircraft.
Quiet Zones		Areas along a rail line where a ban of train horn use is in effect
Rail Diesel Car	RDC	A self-propelled, diesel-powered rail passenger car originally built by the Budd Company of Philadelphia between 1949 and 1956 (also termed the "Budd Car"). This vehicle was the original "DMU". A remanufactured, Federal Railroad Administration-approved version is available to date.
Rail Sidings		Sidings increase the capacity of a single track. A single-track line has auxiliary tracks known as sidings. Sidings are located along the line, which allows trains moving in opposite directions to pass each other and allows faster trains to overtake slower trains. The capacity of the rail line and the reliability of operation are affected by the time required to move between sidings.
Rail-with-Trail	RWT	Also termed a "Rail-Trail", a RWT is a shared-use path located on, or abutting an abandoned or converted railroad line.
Recission		A congressional budgetary term refering to reduction or cancellation of previously granted funding.
Reclaimed Asphalt Pavement	RAP	Removed and/or reprocessed pavement materials containing asphalt and aggregate produced from pavement materials removed for resurfacing or reconstruction. When crushed and graded, RAP provides a high quality aggregate coated in asphalt that can be blended with conventional aggregates to create aggregate base and surface layer materials that produce roadways with good drainage characteristics and durability. Care must be taken when blending the RAP material with conventional aggregates as it has been found that above 20% to 25% RAP content decreases the strength of the roadway because less compaction of the blended material can be achieved. There are also unresolved environmental concerns regarding the leachability characteristics of RAP where it may be in contact with groundwater.
Record of Decision	ROD	A record of agreement that a proposed project meets all applicable requirements of an EIS. An ROD is issued by the designated lead agency in the study.
Regional Planning Commission	RPC	Enabled by state law, RPCs assist communities within their region to develop local and invoke regional comprehensive land use, transportation and economic development plans which have regulatory recognition in Vermont Act 250 land use proceedings and state agency planning efforts.
Request for Proposal	RFP	A formal invitation to organizations to bid on a scope of work for an outlined project.
Request for Qualifications	RFQ	A formal invitation to organizations to submit their qualifications and merits to undertake a scope of work for an outlined project.
Retroreflective		A type of material on signage or pavement markings used to optimize brightness for the nighttime driver. Retroreflective material make signage legible at further distances by reflecting most all of the light striking it from a light source directly back towards it. This reflection is contained in a narrow cone that spreads out wide enough to include the driver (almost directly behind a vehicle's headlamps). Hence, this special type of "back to the source" reflection is called “retroreflection”. A sign may be reflective, but without this engineered cone of retroreflection, it would be considered "diffuse reflection". When the viewer is not near a light source, many diffuse-reflecting materials will usually be brighter than retroreflective materials.
Ridership		Total number of "rides" taken by people using a public transportation system during a specified time period.
Ridesharing		Any form of shared commuting, which is not Public Transportation (e.g. carpooling, vanpooling, shuttle, etc.).
Right-of-Way	ROW	A pathway or road with a specific description (e.g. 'Access and egress 22 feet wide from the centerline of Main Road in Huntington'). ROW may also entail rights to cross property to go to and from another parcel, to pass across another's land, or right to cross without a specific description (e.g. a floating easement). Railroads own title to a right of way upon which to build permanent tracks.
Riparian Buffer		Riparian buffers are vegetated areas next to water resources that protect water resources from nonpoint source pollution (e.g. vehicles and other traffic) and provide bank stabilization as well as aquatic and wildlife habitat. Buffers can be a strip of grass, shrubs, and/or trees along the bank of a river or stream, which filters pollution and runoff, providing a transition zone between water and human land use.
Road Diet		A term used to convey phenomena of increased safety and reduced traffic congestion via a reduction in the number of travel lanes on a roadway, usually (but not always) from four lanes to three.
Road Surface Management System	RSMS	A program which assists local governments in identifying maintenance and repair strategies for roads.
Roadrailer		Type of equipment involving the use of rubber-tired track trailers fitted on to rail wheelsets, combined with other units to form a train.
Roadway Safety Audit Review	RSAR	A formal safety performance examination of a road or intersection by an multi-disciplinary team. An RSAR reports on potential safety concerns and investigates strategies to improve safety at the specified location. Issues that should be addressed in the report ought to include; 1. Aspects of a safety concern in or around the roadway, and 2. Opportunities to mitigate or eliminate identified safety concerns.
Rolling Stock		Total number of vehicles comprising a transit system (e.g. rail cars, busses, vans, etc.).
Rotary		A large, circular, one-way, multi-lane, and often higher-speed (above 30 MPH) intersection that commonly serves as an access and exit point to interstates, freeways, limited-access highways, or major arterials. Rotaries are NOT roundabouts. Most commonly found in the northeastern U.S., rotaries large size (> 600' width) and low deflection around their center island allow for high speeds (in some cases as high as 45 MPH). Because of this, and Right-of-Way often being given to entering vehicles, rotaries have much higher crash and injury rates than do the more modern Roundabouts.
Roundabout		Non-signalized circular intersection with specific design and traffic control features to ensure low travel speeds and efficient traffic movement.
Route Choice		The process of simulating the sequence of roadways an individual will choose for a trip, given the trip’s origin, destination, and mode.
Route-Miles		Total number of miles within a fixed-route transit system.
Rumble Strips		Rumble strips are raised or grooved patterns constructed on, or in travel lane and shoulder pavements. The texture of rumble strips is different from the road surface. Vehicle tires passing over them produce a sudden rumbling sound and cause the vehicle to vibrate. Road agencies use rumble strips to warn motorists of an upcoming change that may require them to act. For example, the need to slow down for a toll plaza ahead, change lanes for a work zone around the curve, stop for a traffic signal, or steer back onto the roadway. Rumble strips in travel lanes often precede intersections, especially dangerous ones. They are used primarily on expressways, interstate highways, and parkways, although some States install them on 2-lane rural roads that have high numbers of single-vehicle crashes.
Rutting		Surface depression along the wheelpath of a road caused by excessive wear. When rutting occurs, rainwater can collect in the wheelpath, which can lead to increased probability of hydroplaning.
Safe Routes To School	SRTS	Mandated by federal law (SAFETEA-LU), "Safe Routes To School" is intended to benefit children in primary and middle schools (K-8) by encouraging them to walk and bike to school regularly, routinely, and safely. SR2S integrates elements of transportation, economics, health, physical activity, environmental awareness and safety.
Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users	SAFETEA-LU	On 10 August 2005, the new Federal surface transportation act (SAFETEA-LU) was signed into law, authorizing a $286.4 billion transportation program for a 5-year period; FFY 2004-2009. This act covers all surface transportation programs, such as highways, highway safety, transit, freight, and transportation research.
Satellite Facility		Otherwise known as an "Intercept Facility", a Satellite "Park & Ride" facility's purpose is to provide a less expensive parking alternative to on-site locations within activity centers or the urban core area and reduce SOV use in activity centers. These facilities may capture outgoing as well as incoming activity center traffic and serve as a transfer point from car to shuttle or transit. Characteristics include an urban/activity area fringe location, high capacity, surface or structured parking, and high frequency shuttle/transit connections to activity centers. Implementation funding is likely to come from Congressional earmarks and/or public private ventures.
Scenario Planning		A framework and participatory excercise for developing a shared vision for the future by analyzing various forces (e.g. health, transportation, economic, environmental, land use, etc.) which affect a region's growth. Scenario planning is a collaborative process that tests various future alternatives ability to meet regional and community needs.
Scenic Highway		On the recommendation of the scenery preservation council, the transportation board may designate or discontinue any state highway, or portion of a state highway, as a state scenic road. Such action by the legislative body may be petitioned by the registered voters of a municipality pursuant to the provisions of 24 V.S.A. § 1973.
Scoping		A phase in the project development process that moves a recognized problem from an idea through the development of alternatives and environmental screening (also See "Project Development Process").
Shared Use Path		A path separated from vehicle traffic by barrier or open space usually on its own right-of-way.
Sharrow		Otherwise known as a "Shared-Lane Arrow", sharrows are employed on roadways too narrow for striped bicycle lanes and help to provide guidance to bicyclists and warn motorists about the presence of bicyclists. The sharrow is a printed image of a bike symbol underneath two chevrons upon the roadway.
Short Ton		A measure of weight equalling 2,000 lbs. The Short Ton is distinguished from the Long Ton (or British Ton), which equals 2,240 lbs., as well as the Metric Ton, which equals 2,204.62 lbs.
Signal Optimization Analysis		This analysis maximizes roadway mobility and capacity (without undertaking expensive and inconvenient roadway widening projects) and can help to reduce pollution. More specifically, "Signal Optimization" is the efficient use of a municipality's or corridor's traffic signals by improving their timing parameters (Fixed-Cycle, Offset, and Split parameters) within the controller box located at an intersection to lessen acceleration and idle time of vehicles.
Signal Warrant Analysis		As defined by the Manual on Uniform Traffic Control Devices (MUTCD), a Traffic Signal Warrant Analysis is an engineering study of traffic conditions, pedestrian characteristics, and physical characteristics of the location shall be performed to determine whether installation of a traffic control signal is justified at a particular location.
Single Occupancy Vehicle	SOV	Vehicle carrying only a driver.
Single Point Urban Interchange	SPUI	A variation on a "Diamond Interchange", a SPUI can efficiently move large traffic volumes using a smaller footprint (i.e. less land area) than a standard diamond interchange. SPUI's essentially use a single set of signals to control all through and turning traffic. They are typified by a distinctive ‘hour-glass’ shape, giving the device an efficiency advantage that allows for two simultaneous left-hand turning movements at the signalized intersection.
Small Transit Intensive Cities	STIC	Federal program (or formula) intended to support public transportation in smaller urban areas that have transit systems that perform as well or better than systems in larger metropolitan areas (according to six performance categories; 1. Passenger miles traveled per vehicle revenue mile, 2. Passenger miles traveled per vehicle revenue hour 3. Vehicle revenue miles per capita, 4. Vehicle revenue hours per capita, 5. Passenger miles traveled per capita, and 6.Unlinked passenger trips per capita). Only MPOs with urban-area populations of less than 200,000 are eligible for this funding.
Smart Corridor		An area that uses advanced technology to maintain the flow of multimodal traffic at maximum efficiency.
Smart Growth		Programs and policies designed to maximize preservation of undeveloped land, natural, and cultural resources, whilst economically evolving the established developed communities.
Span		The distance a bridge extends between two supports, or a single piece of support frame, which spans the length of the bridge structure.
Special Services Transportation Agency	SSTA	Chittenden County non-profit organization providing paratransit services.
Special Trip Generators		In modeling context, special generators represent employers (or employer locations) with unique characteristics that are especially large and therefore need to be handled outside of the normal trip generation approach. Examples for the Chittenden County, VT model include; IBM (Essex and Williston), the University of Vermont, and Fletcher Allen Health Care.
Speed Bumps		A Speed Bump is also a raised pavement area across a roadway. Speed bumps are typically found on private roadways and parking lots and do not tend to exhibit consistent design parameters from one installation to another. Speed bumps generally have a height of 3 to 6 inches (76 to 152 mm) with a travel length of 1 to 3 feet (0.3 to 1 m). From an operational standpoint, speed bump impacts within typical residential operational speed ranges slow vehicles to about 5 mph or less at each bump. Speed bumps of varying design have been routinely installed on private roadways and parking lots without the benefit of proper engineering study regarding their design and placement.
Speed Humps		A Speed Hump is a raised area in the roadway pavement surface extending transversely across the travel way. Speed humps are sometimes referred to as "pavement undulations" or "sleeping policemen". Most agencies implement speed humps with a height of 3 to 3.5 inches (76 to 90 mm) and a travel length of 12 to 14 feet (3.7 to 4.3 m). Speed humps are generally used on residential local streets. From an operational standpoint, speed humps impact within typical residential operational speed ranges, slow vehicles to about 20 mph (32 km/h) on streets with properly spaced speed humps. Speed humps have evolved from extensive research and testing and have been designed to achieve a specific result on vehicle operations without imposing unreasonable or unacceptable safety risks.
Speed Tables		Speed Tables are essentially flat-topped speed humps, and may have a textured material on the flat section with asphalt or concrete for the approaches. Speed tables are sometimes referred to as "trapezoidal humps" or "speed platforms". If marked as a pedestrian crossing, speed tables may also be referred to as "raised crosswalks" or "raised crossings". Most agencies implement speed tables with a height of 3 to 3.5 inches (76 to 90 mm) and a travel length of 22 feet (6.7 m). Speed tables generally consist of 10 foot (3.1 m) plateau with 6 foot (1.8 m) approaches on either side that can be straight, parabolic or sinusoidal in profile. The longer lengths of speed tables provide a gentler ride than speed humps and generally result in vehicle operating speeds ranging from 25 to 30 mph (40 to 48 km/h) on streets depending on the spacing between speed tables. Speed tables are generally used on residential collectors, emergency routes or transit routes.
Splitter Islands		A dual-purpose component of a roundabout that serves to deflect traffic speed of entering and exiting vehicles, as well as provide a temporary refuge to pedestrians where crossing is permitted along roadway approaches.
Sprawl		See; "Urban/Sub-Urban Sprawl"
Standard Land Use Coding Manual	SLUCM	Developed by the Housing and Urban Development Agency in 1965, SLUCM was a predecessor to the more current LBCS (APA's Land-Based Classification Standards). The 1965 SLUCM provided a numeric coding schema using two, three, four, or more digits identifying land-use categories. An additional two to eight digits identified Ownership, Type of Structure an activity was housed, and Secondary Use Codes identifying additional land uses. SLUCM land uses categories were derived from Standard Industrial Classification (SIC) codes.
State Implementation Plan	SIP	Clean Air Act plan which identifies how the state will attain and/or maintain NAAQS standards.
State Planning and Research Funds	SPR	Funds intended for planning and research purposes. SPR funding requires that States allocate 2 percent of their apportionments received from federal programs (e.g. Interstate Maintenance, NHS, Surface Transportation, Highway Bridge, CMAQ, et al.) for State planning and research activities. From this 2 percent, States must then allocate 25 percent for research, development, and technology (RD&T).
Statewide Transportation Improvement Program	STIP	The State’s four-year list of fiscally constrained transportation projects planned for implementation statewide.
Stopping Sight Distance	SSD	The minimum distance a driver can see ahead in tandem with how long it takes for her/him to stop. According to the AASHTO "Green Book", this distance is comprised of two components; 1. Perception-Reaction Time, which covers the distance a vehicle travels from the moment the driver sees an object necessitating a stop, to the instant the brakes are applied, and -- 2. Braking Distance, which is the distance a vehicle travels during the braking maneuver.
Strategic Highway Network	STRAHNET	A network of highways which are important for U.S. strategic defense policy and which provide defense access, continuity and emergency capabilities for defense purposes.
Strategic Highway Safety Plan	SHSP	Required by federal law (SAFETEA-LU, 2005), An SHSP identifies a State's key safety needs, whilst guiding investment decisions to achieve significant reductions in highway fatalities and injuries on all public roads. The SHSP facilitates all State highway safety programs to work in concert to align all its resources to collectively address safety challenges on all its public roads.
Sub-base (of Road)		The load bearing and distribution layer of a road underneath the pavement and capping layer. The sub-base is often made of an aggregate such as gravel or crushed-concrete, which is spread and compacted in-place during construction. A Sub-base might also be made of a bound concrete slab in the case of a weak subgrade, or when heavy loads are expected upon the roadway.
Subgrade (of Road)		Classically known as the "Formation Level", the subgrade of a road is the underlying layer beneath the sub-base. The subgrade is at the lowest level of excavation for a road structure and is leveled off to serve as the foundation. A good subgrade should be at least compacted soil that has a low-permeability.
Substantial Regional Impact	SRI	In the context of the State of Vermont planning practice, a proposed development has a Substantial Regional Impact (SRI) if a policy of this Regional Plan that is relevant to the determination of an issue in an Act 250 or Section 248 proceeding makes recommendations that are more specific about one or more characteristics, features, standards, or conditions relating to the proposed development than the recommendations of the municipal plan.
Sufficiency Rating		A measure of road or bridge adequacy. A section of road that is completely adequate in every respect is rated at 100. Any deficiency in the road that affects the structural condition, efficient movement of traffic, or safety reduces the rating as far down as zero.
Sulfur Dioxide	SO2	Petroleum fuels contain traces of sulphur compounds and produce Sulfur Dioxide (SO2) during combustion. The majority of the SO2 pollution comes from power generation, which is a significant cause of "Acid Rain". Except for the shipping mode, transportion is not a major contributing source of SO2.
Super Ultra Low Emission Vehicle	SULEV	A vehicle producing 90 percent less pollutants than an average gasoline-powered vehicle for the year of manufacture.
Supply Chain Consortium	SCC	A private-sector consortium which collects data, develops indicators, advises on "Best Practices" optimizing performance and profitability of a supply chain.
Supply Chain Management	SCM	Planning and management of business activities involved in movement of freight. SCM seeks to equalize supply and demand across all tiers of the chain (e.g. Supplier -- Primary Manufacturer -- Secondary Manufacturer -- Regional Warehouse -- Distributor -- Retailer -- Consumer).
Surface Transportation Program	STP	Federal program providing flexible funding for projects on any Federal-aid highway, including the NHS, bridge projects on any public road, transit capital projects, and bus facilities.
Swept Path Width		Amount of roadway covered in negotiating a turn; equals the "offtracking" width (i.e. The difference between the front and rear wheelpaths when a bus or truck is negotiating a turn) plus the tractor unit or bus width.
Tax Increment Finance District	TIF	Locally designated area receiving targeted investments from increased property tax revenue.
Technical Assistance	TA	The CCMPO technical assistance program provides technical support relating to transportation issues for member municipalities and agencies. Services typically provided through this program include: Traffic Counts, Speed Limit Recommendations, Traffic Signal Optimization, Traffic Control Warrant Analysis, Roadway Surface Management Studies, Small Area Transportation Studies, and Safety Studies.
Telecommunications Display Device	TDD	Apparatus that converts telephoned information to visual form on a computer screen. Useful to hearing or speech-impaired individuals.
Telecommuting		Telecommuting or telework enable potential commuters to work outside the traditional office or workplace, usually at home or in a mobile situation, communicating electronically (by telephone, internet, or teleconference, etc.) with an office from home instead of traveling to it physically.
Throughput		Total amount of freight imported or exported via a freight facility measured in TEUs or tons over a given period of time.
Ton-Mile		The movement of 1 ton of cargo the distance of 1 mile. Ton-miles are calculated by multiplying the weight in tons of each shipment transported by the miles hauled.
Traffic Analysis Zone	TAZ	Chittenden County is divided into 335 small areas. Each area has relatively similar characteristics within its boundaries. Often derived from Census Blocks, or Block Groups, TAZs represent land use data on housing and employment in the Travel Demand modeling process.
Traffic Assignment		In the four step practice of Travel Demand Modeling, Traffic Assignment is the process of predicting the specific path travelers take from their Origin to their Destination.
Traffic Calming		The use of education, enforcement, and engineering to change the behavior of drivers and increase safety.
Traffic Circle		Traffic circles (or rotaries) are intersections designed for high speed entry and multi-lane maneuvering. Historically, many have given driver Right-of-Way to entering vehicles, causing gridlock and traffic congestion. Because traffic circles suffered high crash rates and operational problems, they fell out of favor in the US during the 1950s and 1960s. Traffic circles are NOT Roundabouts.
Traffic Impact Study	TIS	Also known as Traffic Impact Analysis (TIA), these are studies which collect and analyze information to determine need, impact, and impact mitigation for major roadway improvements. Some activities of a TIS include; Traffic counts, Crash evaluation, Capacity & Level Of Service calculation, Signal Warrant analysis, Development of condition diagrams, Forecasting future traffic volumes with new development and/or alternatives.
Trailblazers		Directional signs placed at strategic locations along high-volume roads, indicating direction to convenient routes or points of access to facilities.
Trailer-on-Flatcar	TOFC	A shipping container capable of transport upon a rail flat car or truck flat bed trailer. Same as COFC.
Train-Mile		The movement of a train, which can consist of many cars, the distance of one mile. A train-mile differs from a vehicle-mile, which is the movement of one car (vehicle) the distance of one mile. A 10-car (vehicle) train traveling 1 mile is measured as 1 train-mile and 10 vehicle-miles. Caution should be used when comparing train-miles to vehicle-miles.
TransCAD		A computer software “platform” used for the CCMPO transportation model.
Transit		Generally refers to urban passenger transportation service, (private or public) along established routes with fixed or variable schedules at published fares.
Transit Options		Infrastructural refinements which assist commuters with intermodal intermodal transitions. Examples of Transit Options are; Trail connection to bus, rail or ferry station, Bike racks on buses, Bike parking/rental/sharing at transit stations, Improved pedestrian access to transit, Long-term bike storage at Park & Rides or transit centers, et al.
Transit-Oriented Design	TOD	High density and mixed use land development around transit system stops.
Transit-Oriented Development	TOD	Mixed-use (residential, commercial, and industrial) development and zoning designed around commuter rail or bus facilities and infrastructure.
Transit-Ready Development	TRD	Similar to TOD, TRD prepares a neighbourhood, corridor, or area for future transit expansion with neighbourhood densities, road networks, pedestrian infrastructure, and public facilities designed as transit destinations.
Transload		Transload facilities provide shippers/receivers with access to rail transportation and storage capacities that otherwise would be unavailable. This enables a local business to purchase a rail car load of product at a lower price per unit, and provides opportunities for several shippers/receivers to consolidate their freight to take advantage of the economies offered by rail. This translates into lower costs and reduced dependence on trucks. Facility features may include; cranes, forklifts, undertrack unloading equipment, conveyors, truck and rail car scales, and rail moving equipment to expedite placement of rail cars for loading and unloading.
Transportation Action Grant	TAG	A CCMPO sponsored competitive planning grant program designed to encourage innovative, action-oriented transportation planning initiatives in Chittenden County.
Transportation Advisory Committee	TAC	A committee that recommends plans and programs to the CCMPO Board (formerly know as the Technical Advisory Committee).
Transportation Capital Program		The annual program devised by the State of Vermont to determine and prioritize transportation capital investments statewide. These needs and cost estimates are updated annually in the program. This process is coordinated with the CCMPO through the TIP development process.
Transportation Control Measures	TCM	Actions, which are usually found in a State Implementation Plan (SIP), that improves traffic flow, reduce vehicle use, or decrease congestion with the objective of lessening air pollutant emissions.
Transportation Demand Management	TDM	Low-cost programs that focus on decreasing travel and the use of SOVs, and increasing the use of other modes.
Transportation Enhancement Program	TE	Federal funding program for projects designed to enhance transportation related quality of life. Such projects and programs generally relate to such activities as; Bicycle and pedestrian infrastructure and safety programs, Scenic and historic highway programs, Landscaping and scenic beautification, Historic preservation, and Environmental mitigation.
Transportation Equity Act for the 21st Century	TEA-21	Enacted in July 1998, TEA-21 calls for integrating all modes of transportation - cars, trains, trucks, buses, ferries, walking and biking - into a single, efficient and 'seamless' transportation system. It mandates greater local control over transportation funding decisions through MPOs, such as the CCMPO.
Transportation for Livable Communities	TLC	A CCMPO grant program that supports development that strengthens the link between transportation investments and community livability.
Transportation Improvement Program	TIP	A list of federally funded projects planned for a four-year period and consistent with the goals of the MTP.
Transportation Management Area	TMA	An area designated by the US Secretary of Transportation, having an urbanized area population of over 200,000, or upon special request from the Governor and the MPO, or under special circumstances designated for the area.
Transportation Management Association	TMA	A voluntary association of public organizations, private agencies, and businesses joined to develop cooperative transportation programs in a given area.
Transportation Planning Initiative	TPI	An effort by VTrans to ensure that the public plays a significant role in determining which transportation problems to be addressed and the scale of those improvements.
Transportation Research Board	TRB	TRB is one of six major divisions of the National Research Council, advising the President and Congress specifically on the development of transportation. TRB is a forum engaging engineers, scientists, and other transportation researchers and practitioners from the public, private, and academic sectors to promote progress and innovation through interdisciplinary research.
Transportation Systems Management	TSM	Low-cost projects that focus on how the transportation system responds to people’s needs. Most examples are in intersection and signal improvements, such as; signal timing optimization, controller/cabinet and signal head upgrades, vehicle detectors repair/replacement, turning lanes, grade separations, pavement striping, lane assignment changes, signage and lighting.
Transportation, Community and System Preservation Program	TCSP	Federal program that provides funding for planning grants, implementation grants, and research to investigate and address the relationships between transportation, community and system preservation.
Travel Demand Forecasting (Modelling)	TDF	A four-step (some consider it a five-step) process used to predict future traffic on a transportation network. The five steps, in order, are; 1. Trip Generation, 2. Trip Distribution, 3. Mode Split/Mode Choice, 4. Traffic Assignment, and 5. Model Validation and Reasonableness Checks.
Trigger		The value of a measurable indicator (e.g. average daily traffic, volume-to-capacity ratio, population density) that, when reached, will cause a set of agreed-upon actions to be taken (e.g. conduct traffic study).
Trip Attraction		The process of attracting trips to a zone. It is generally a function of the land uses in a zone.
Trip Distribution		The process of determining trip exchanges; the number of trips between each pair of zones.
Trip Generation		The first step in the four-step Travel Demand Modeling process, which estimates the number and types of trips types taken by travelers (e.g. Home-To-Work, Nonwork-To-Home, etc.).
Trip Reduction Ordinance	TRO	Local regulations requiring employers, developers, or housing managers to provide incentives for workers or residents to use alternative modes of transport.
Truck Apron		Component of a roundabout central island, which accommodates the "Offtracking" of large trucks or buses, but is not intended to be driven by automobiles. Truck aprons generally are a raised and widened concrete or brick pad constructed along the perimeter of the central island.
Truck Load	TL	"Truckload", or "Full Truckload" carriers (FTL or TL) usually haul freight in single moves from shipper to receiver (See FTL for a more detailed description).
Truck Network		Road network designated for freight truck travel. The national network has no overall vehicle length limits, nor permit requirements (e.g. I-9, I-89, I-189, and parts of US 7 & US 4). The Vermont network requires permits for any vehicles longer than 72'. The remainder of state highways (not on the truck network) require a permit for trucks and have a 68' vehicle length limit.
Truss		A framed structure of a bridge, comprised of a series of triangles or other stable shapes (made from a network of connected beams). A "plane truss" example is where all members and joints lie within a 2-dimensional plane, while a "space truss" has members and joints extending into 3 dimensions.
Twenty-Foot Equivalent Unit	TEU	A Twenty-Foot Equivalent Unit is used to express shipping or capacity volume of freight. Using the ISO standard of a 20-foot shipping container as a means of measurement, TEUs further summarise a general sense of freight traffic moving through major shipping ports commonly reported by government or industry. A TEU is an approximate measure of containerized cargo capacity (20 ft. long * 8 ft. wide container), which does not account for container height.
Typical Day		A weekday exhibiting travel patterns which occur on a regular basis. Generally, there is standard practice for collecting traffic-related data on Mondays through Thursdays of weeks without holidays or other occurrences that arguably influence travel patterns.
Ultra Low Emission Vehicle	ULEV	A vehicle producing 50 percent less pollutants than an average gasoline-powered vehicle for the year of manufacture.
Underdrain		A drainage structure buried to the subgrade level along the edge of the roadway. Underdrain components usually include geotextiles, uniform coarse stone (free draining material), and a pipe. The underdrain works by providing an opportunity for excess water in the adjacent subgrade layer to drain away, while keeping the soil particles in place. Underdrains can be used under or near drainage ditches on almost any cut slope sections, especially where water seeps to the surface or other evidence of excess water is present.
Unified Planning Work Program	UPWP	The CCMPO’s annual work plan for local and regional transportation planning projects.
United States Department of Transportation	USDOT	A federal department of the United States government overseeing transportation, established by Congress in 1966.
United We Ride	UWR	Federal initiative created by Executive Order #13330 intended to break down the barriers among Federal programs as they relate to transportation to ensure that transportation services are seamless, comprehensive and accessible. Specifically, UWR is tasked with seeking ways to simplify access to transportation services for persons with disabilities, persons with lower incomes, and older adults.
Unlinked Passenger Trips	UPT	Total number of passengers who board public transportation vehicles. It should be noted that passengers are counted each time they board vehicles no matter how many vehicles they use to travel from their origin to their destination
Urban Growth Boundary	UGB	A regional boundary, which is created to efficiently utilise land and regulate urban/sub-urban development into agricultural, forest lands, and other natural areas. By zoning high density development within the UGB, there is greater leverage to encourage the continual redevelopment of land and buildings within urban cores (thereby keeping "downtowns" active), as opposed to unabated land consumption encroaching into natural areas. UGBs can further reduce infrastructure and transportation expenses by maintaining a local compact development strategy.
Urban Traffic Management System	UTMS	ITS applications focused on traffic efficiency improvements in an urban area.
Urban/Sub-Urban Sprawl		A scattered, untimely, and poorly planned urban or sub-urban development occurring in urban/sub-urban fringe, as well as rural areas. It is an inefficient policy and planning practice, which consumes land necessary for agricultural or natural resource protection. "Sprawl" typically manifests in the form of; "Leapfrog" development, "Strip-mall" or "Ribbon" development, and large-lot single family units. A term describing the antithesis is known as "Smart-Growth".
Urbanized Area	UA	First delineated in the 1950 Census, urbanized areas are densely settled territory, which the U.S. Census Bureau defined from 1950 to 1990 as having a population of 1,000,000 or more. Since the 2000 Census, Urbanized Areas are defined as: Core census block groups or blocks that have a population density of at least 1,000 people per square mile, and a total population of 50,000 or greater. Areas of the same population density, but having a total population ranging from 2,500 to 50,000 are defined in the 2000 Census as an "Urban Cluster" (UC).
Validation		The process of evaluating the accuracy of a transportation model.
Vanpool		A service where passengers share the use and expense of a van to commute to work.
Variable Message Sign	VMS	Electronic highway signs where the displayed message can be changed to inform motorists of diferent road, traffic, or weather conditions, etc.
Vehicle Hours of Delay	VHD	An indicator reflecting the time it takes to travel a roadway during peak periods v.s. the time it would to travel at a free-flow 35 miles per hour.
Vehicle Hours of Travel	VHT	Transportation performance measure that considers the amount of time trip-making takes.
Vehicle Miles Traveled	VMT	An indicator of occuring traffic, calculated using Annual Average Daily Traffic (AADT) multiplied by the length of a particular road in question. One car traveling one mile represents 1 unit of VMT.
Vehicle Trip		An Origin-to-Destination journey by a single vehicle. A bus carrying 40 people from an origin to a destination makes one vehicle trip, while its occupants make a total of 40 person trips.
Vehicles Per Day	VPD	Traffic Volume or Capacity is generally expressed in "Vehicles Per Day" or "Vehicles Per Hour".
Vermont Agency of Transportation	VTrans	Agency that establishes state policies and plans, and implements programs and projects, for all modes of transportation.
Vermont Association of Planning & Development Agencies	VAPDA	Organization comprised of Regional Planning Commission directors and the Chittenden County MPO director, chartered to coordinate a combination of environmental and economic planning strategies
Vermont Association of Snow Travellers	VAST	VAST is Vermont's non-profit, private volunteer snowmobiling organization, responsible for maintenance of Vermont trails. VAST has thousands of members and is one of the oldest such organizations in the U.S.
Vermont Center for Geographic Information	VCGI	Initiated in 1994, under Act 204 (10 VSA Chapter 8), the Vermont Center for Geographic Information, Inc. (VCGI) is a non-profit public corporation tasked with the development and management of GIS data, and coordination of GIS activities for the State of Vermont.
Vermont League of Cities and Towns	VLCT	Founded in 1967, VLCT is a nonprofit, non-partisan organization serving Vermont municipal officials.
Vermont Local Roads Program		The Vermont Local Roads Program at Saint Michael’s College is part of the Local Technical Assistance Program (LTAP), a nationwide effort financed jointly by the Federal Highway Administration (FHWA) and individual State Departments of Transportation. Its purpose is to provide road and bridge know-how to municipal people involved with highways. There are LTAP Centers in 50 states and Puerto Rico and six Native American locations.
Vermont Online Bridge & Culvert Inventory Tool	VOBCIT	An online user-friendly application to record and update bridge and culvert data for structures owned by communities in Vermont. The Vermont Agency of Transportation (VTrans) was directed by the Vermont Legislature to complete and deploy an integrated software product to handle data entry, access and status reporting of town bridge and culvert inventories currently collected by Regional Planning Commissions (RPCs), the Chittenden County Metropolitan Planning Organization, municipalities, and their contractors. Data within VOBCIT complies with the state "Bridge & Culvert Data Exchange Standard".
Vermont Planners Association	VPA	A Vermont membership-based, non-profit organization of professional planners, citizen planners, landscape architects, engineers, housing and economic development specialists, and developers.
Vermont Rail Advisory Council	VRAC	Instituted in 1993, VRAC was created to advise the Governor and The Agency of Transportation on rail issues. Meeting about 5-6 times per year, members are recruited from private rail industry, operators on state-owned railroads, freight shippers, environmental and economic development organizations, regional chambers of commerce, regional planning commissions, the House & Senate Transportation Committees, and travel and recreation organizations.
Vermont Rail Advocacy Network	VRAN	A grassroots network of advocates promoting greater rail mode utilization for passenger and freight in Vermont.
Vermont Railway	VTR	A privately operated railroad company.
Vermont State Standards	VSS	Formally known as the "Vermont State Standard for the Design of Transportation Construction, Reconstruction and Rehabilitation on Freeways, Roads and Streets", VSS was developed during the mid-1990's, standardizing the physical design parameters and guidelines of Vermont bridges and roadways. VSS was initially created for two purposes: 1. To provide clear technical direction to the designers of transportation projects in Vermont. AND: 2. To achieve roadway and bridge designs which provide access, mobility and safety for users, and which are also sensitive to the social and environmental context of Vermont.
Vermont Statutes Annotated	VSA	The official codification of the laws enacted by the Vermont General Assembly (i.e. Legislature).
Vermont Transportation Authority	VTA	Operator of passenger rail services.
Viewshed		The area within view of a defined observation point or corridor.
Volatile Organic Compounds	VOC	A group of chemicals that reacts in the atmosphere with NOx in the presence of heat and sunlight to form ozone. Examples include gasoline fumes and oil-based paints.
Volume to Capacity Ratio	V/C	An indicator of congestion levels measured by the number of vehicles per hour (volume) divided by the maximum number of cars the road is designed to handle (capacity).
Warrant Analysis		A process outlined by the Manual on Uniform Traffic Control Devices (MUTCD) which helps determine whether an intersection meets the criteria for the installation of a traffic signal or stop signs.
Way To Go Week	W2GW	Vermont annual TDM program that encourages the population to commute non-SOV for one week in the month of May.
Waybill		A receipt evidencing contract and instructions for the transport of cargo. Otherwise known as a "Bill of Lading".
Weigh-in-Motion Detectors	WIM	A device employed to capture specific truck-axle or gross vehicle weight as trucks travel over a sensor. Such information is useful in highway or bridge design, as well as truck size and weight enforcement.
Wye		A railroad connector shaped like the alphanumeric character "Y". A wye serves to assist in redirecting rail traffic or reverse direction of travel of a locomotive.
Yellow Book		Originally published by the U.S. Bureau of Public Roads (predecessor to FHWA) in 1955, The "Yellow Book", is officially titled; "General Location of National System of Interstate Highways, Including All Additional Routes at Urban Areas Designated in September, 1955". This publication outlined the original plan for the Interstate Highway System with included maps.
Yield-to-Left	Y2L	Principle where circulating vehicles within a roundabout, traffic circle, or rotary have the Right-of-Way over entering vehicles. Such practice eliminates traffic gridlock within the intersection. However this policy may vary by state, region, or other jurisdiction.
Zero Emission Vehicle	ZEV	Vehicles which do not produce tailpipe and evaporative emissions, where emission-control systems cannot fail, and do not cause emissions from gasoline purchase or its refinement. Of the vehicles which fall in this classification are; Bicycles, Electric vehicles, Compressed-air vehicles, Fuel-cell vehicles, Solar & Hydrogen-powered vehicles, and other human or animal-powered vehicles.
Zoning		Local government laws controlling the use and development of land within a jurisdiction.
Zoning Administrator	ZA	Local administrator in charge of enforcing municipal zoning regulations. The ZA also is responsible for providing information to the public, reviewing plans and documentation for compliance, and assisting applicants with their requests for variances.
Zoning Board of Adjustment	ZBA	A municipal-level, quasi-judicial body responsible for issuing Zoning Variances, Conditional Use Permits, and hearing appeals. The ZBA interprets the intent of law and sets local land use policy.

OTHER TRANSPORT TERMINOLOGY REFERENCES: