Glossary Of Transportation Planning Terms And Acronyms

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Access Management	The process of providing and managing access to land development while preserving the regional flow of traffic in terms of safety, capacity, and speed.
ADT	Average Daily Traffic. This is typically measured as the total traffic volume passing a point or segment of a road facility, in both directions as measured in a 24-hour period.
Alternatives Analysis (AA)	A detailed study of a transit corridor. An alternatives analysis focuses on alternative transit solutions to the transportation problems identified during the Pre-AA. An AA will include a range of alternatives including one or more rail options, a bus guideway alternative, and a non-guideway (TSM) alternative representing the best solution possible without an investment in new infrastructure.
Americans with Disabilities Act (ADA)	A 1990 Federal law mandating sweeping changes in building codes, transportation, and hiring practices to prevent discrimination against persons with disabilities, not only in projects involving federal dollars, but in connection with all new public places, conveyances, and employers.
Arterial	A major street carrying the traffic of local and collector streets to and from freeways and other major streets. Arterials generally have traffic signals at intersections and may have limits on the driveway spacing and street intersection spacing.
Bus Rapid Transit (BRT)	BRT is an integrated bus-based "rapid" transit system utilizing highly-flexible service and advanced technologies to improve customer convenience and reduce delays. BRT can operate on exclusive transitways, HOV lanes, expressways, or ordinary streets. Main features include modern low-floor buses, signal priority at intersections, maximum off-vehicle fare collection, reduced headways, real-time information displays, and modern stations.
Capacity	The maximum rate of flow at which vehicles can be reasonably expected to traverse a point or uniform segment of a lane or roadway during a specified time period under prevailing roadway, traffic, and control conditions; usually expressed as vehicles per hour.
Clean Air Act Amendments of 1990 (CAAA)	A 1990 Federal law that identifies "mobile sources" (vehicles) as primary sources of pollution and calls for stringent new requirements in metropolitan areas and states where attainment of National Ambient Air Quality Standards (NAAQS) is, or could be, a problem.
Collector Streets	Collector streets connect local traffic within a subarea of the county to arterial roads. Typically collector streets are not continuous for any great length nor do they form a connected network by themselves. Collectors connect neighborhoods to commercial areas. Pedestrian and bicycle activity is moderate to high.
Commute Trip Reduction Law	A 1991 Washington State law that requires major employers in the eight most populous counties in the State to take measures to reduce the number of single-occupant vehicle (SOV) trips and number of vehicle miles traveled (VMT) by their employees. SOV trips and VMT are targeted to be reduced from a baseline year within homogeneous trip-reduction zones by 15 percent in 1995, 25 percent in 1999, and 35 percent in 2005. When new employers are brought into the program, the goals are a reduction of 15% after two years, 20% after four years, 25% after 6 years, and 35% after twelve years.
Commuter Rail	The portion of passenger railroad operations that carries passengers within urban areas, or between areas and their suburbs, but differs from rail rapid transit in that passenger cars generally are heavier, average trip lengths are longer, and operations are carried out over tracks that are part of the existing freight railroad system in the area.
Comprehensive Plan	A document consisting of maps, charts, and text which contains the adopting city or county's policies regarding long-term development. A comprehensive plan is a legal document required of each local government by the State of Washington.
Concurrency	The Concurrency ordinance was adopted in response to the Washington State Growth Management Act, which required local jurisdictions to adopt level-of-service (LOS) standards for the arterial road system and to ensure maintaining those standards when considering new development. This process is called "Concurrency". Concurrency applies to any development, land division, site plan, and conditional use permit approvals.
C-TRAN	Public transit agency providing bus, paratransit and other services in Clark County. Known formally as the Clark Public Transportation Benefit Area Authority.
Draft Environmental Impact Statement (DEIS)	A detailed analysis of the effects on the environment of a proposed development or land-use. The environmental analysis includes potential impacts on areas such as air, noise, and water quality.
Federal Highway Administration (FHWA)	The agency of the United States Department of Transportation with jurisdiction over highways.
Federal Transit Administration (FTA)	The agency of the United States Department of Transportation with jurisdiction over transit. Formerly the Urban Transit Administration.
Feeder Service	Local transit service that provides access to other, usually faster and higher capacity, transit service.
Functional Classification System	The system classifies transportation facilities according to an appropriate integrated network. It is intended to link land use development activities with transportation for optimum utilization of both. The county's classification system is intended to be in compliance with the federal classification system.
Growth Management Act (GMA)	A 1990 Washington State law, amended in 1991, designed to address the negative consequences of unprecedented population growth and suburban sprawl in Washington. The GMA requires all cities and counties in the State to do some planning and has more extensive requirements for the largest and fast-growing counties and cities in the State. Its requirements include guaranteeing consistency between the transportation, capital facilities and land use plans.
High Capacity Transit	High capacity transit is characterized by carrying a larger volume of passengers using larger vehicles and/or more frequent service than a standard fixed route bus system. High capacity transit can operate on exclusive rights-of-way such as a rail track or dedicated busway, or on existing streets with mixed traffic. The main goal of high capacity transit is to provide faster, more convenient and more reliable service for a larger number of passengers.
High Occupancy Vehicle (HOV)	A type of transportation vehicle that carries several passengers at one time. Typical examples include rail transit, bus transit, vanpools, and carpools.
Impact Fee	A fee imposed on a developer to help finance the cost of infrastructure improvements and/or increased service caused by new development.
Interchange	A system of interconnecting roadways in conjunction with one or more grade separations, providing for the movement of traffic between two or more roadways on different levels.
Intermodal Surface Transportation Efficiency Act (ISTEA)	Federal law passed in 1991, provides state and local transportation planners and decision-makers with the flexibility to fund transportation projects, which best meet locally determined goals and objectives for mobility, economic opportunity, and air quality. In addition, ISTEA allows for the flexible use, with some restrictions, of selected traditional Federal Highway and Transit funding sources. In 1998 a new Federal Transportation Act, TEA-21, was passed which succeeds ISTEA.
Intersection	The general area where two or more highways join or cross, within which are included the roadway and roadside facilities for traffic movements in that area.
Level Of Service (LOS)	The 'Level of Service' is a grading system developed by the transportation profession to quantify the degree of comfort (including such elements as speed, travel time, number of stops, total amount of stopped delay, and impediments caused by other vehicles) afforded to drivers as they travel through an intersection or roadway segment. LOS is expressed as a letter grade that ranges from "A", indicating that drivers will experience little, if any delay, to "F", indicating significant traffic congestion and driver delay will occur.
Light Rail Transit (LRT)	LRT is a system of modern rail cars or a single rail car operating on a rail track in exclusive rights-of-way, or in the street with mixed traffic. Light rail cars commonly powered by an overhead catenary and electric line, or by an on-board diesel or electric motor. Main features include rail vehicles, rail tracks, overhead electric lines, modern rail stations, signal priority at intersections, and integration with transit-oriented development strategies.
Locally Preferred Alternative (LPA)	The mode, alignment and termini location selected for the development of a high capacity transit (HCT) system by local jurisdictions following the conclusion of the Alternatives Analysis process.
Metro	The designated MPO for the three-county Portland metropolitan area overseeing Multnomah, Washington, and Clackamas Counties.
Metropolitan Planning Organization (MPO)	The agency designated by the governor to administer the federally required transportation planning process in a metropolitan area. An MPO must be in place in every urbanized area over 50,000 population. The MPO is responsible for the 20-year long-range plan, the Metropolitan Transportation Plan (MTP), and the Metropolitan Transportation Improvement Program (MTIP).
Metropolitan Transportation Plan (MTP)	The official intermodal transportation plan that is developed adopted through the metropolitan transportation planning process for the metropolitan planning area, in accordance with 23 U.S.C 134, 23 U.S.C 135 and 49 U.S.C 5303.
Mobile Source	Mobile sources are referred to as contributors to pollution. Some examples include motor vehicles, aircraft, seagoing vessels, and other transportation modes. The mobile source-related pollutants are carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (Nox), and small particulate matter (PM-10).
Mode	The means by which a travel trip is accomplished. Examples of different modes include auto, bus, bicycle, and walking.
National Ambient Air Quality Standards (NAAQS)	Federal standards that set allowable concentrations and exposure limits for various pollutants. The EPA developed the standards in response to a requirement of the CAA.
National Environmental Policy Act (NEPA)	Established a national environmental policy requiring that any project using federal funding or requiring federal approval, including transportation projects, examine the effects of proposed and alternative choices on the environment before a federal decision is made.
National ITS Architecture	A systems framework to guide the planning and deployment of ITS infrastructure. The national ITS architecture is a blueprint for the coordinated development of ITS technologies in the U.S. It is unlikely that any single metropolitan area or state would plan to implement the entire national ITS architecture.
Non-Attainment Area	A non-attainment area does not meet National Ambient Air Quality Standards. The Portland-Vancouver region was classified as a non-attainment region for both carbon monoxide and ozone but is currently classified as an air quality maintenance area.
Off-Peak Period	A specified time period in which the volume of traffic is lower than that during peak hours. Those periods of the day where demand for transit service is not at a maximum.
Ozone (O3)	Ozone is a colorless gas with a sweet odor. Ground level ozone is not a direct emission from transportation sources. It is a secondary pollutant formed when volatile organic compounds, such as pesticides and solvents, and NOx combine in the presence of sunlight. Although the ozone in the upper atmosphere protects us from harmful ultraviolet rays, ground-level ozone is the main component of smog.
Paratransit	A transportation service provided to individuals with disabilities who are unable to use traditional public transportation. In 1985, C-TRAN formally established C-VAN as C-TRAN's paratransit program with the focus and responsibility of providing specialized transportation services for Clark County.
Park-and-Ride	A lot that provides all day parking facilities for automobiles. Park-and-Ride lots are typically located near the fringe areas of a transit system where feeder bus service is sparse or nonexistent.
Peak Hour	A period of 60 consecutive minutes during which an intersection or roadway system experiences the greatest amount of traffic volume.
Peak Period	A specified time period in which the volume of traffic is greater than off-peak periods. Those periods of the day where demand for transit service is at a maximum.
Performance Measures	Indicators of how well the transportation system is performing with regard to such things as average speed, reliability of travel, and accident rates. Used as feedback in the decision making process.
Planning Funds	Primary source of funding for metropolitan planning designated by the FHWA.
Public Participation	The active and meaningful involvement of the public in the development of transportation plans and programs.
Regional Transportation Plan (RTP)	A plan to coordinate long-range transportation planning efforts of all member jurisdictions. The federal government requires that an RTP be developed by Metropolitan Planning Organizations (MPOs) and Washington state requires that all state Regional Transportation Planning Organizations (RTPOs) develop an RTP. In Clark County, the RTP is also known as the Metropolitan Transportation Plan (MTP).
Regional Transportation Planning Organization (RTPO)	RTPOs were authorized by the Legislature in 1990 as part of the Growth Management Act (GMA). RTPOs are created by local governments to coordinate transportation planning among jurisdictions and to develop a regional transportation plan. Washington provides funding and a formal mechanism that is available to all local governments and the State to coordinate transportation planning for regional transportation facilities.
Right-of-Way	A general term denoting land, property, or interest therein, usually in a strip, acquired for or devoted to transportation purposes. The corridor (horizontal and vertical space) occupied by the transportation way.
Roadway Section	A roadway section is a cross-section of a roadway which displays, travel lanes, turning lanes, bike.
Shared Parking	A parking area that can adequately serve two or more uses with different peak-use periods. An example of shared parking is a movie theater parking lot being used for park and ride patrons during the day and movie-goers in the evening.
Single Occupancy Vehicle (SOV)	An automobile being used by only one person (i.e. one driver and no passengers).
Smart Growth	A set of policies and programs designed to protect, preserve, and economically develop established communities and valuable natural cultural resources.
Sources	Refers to the origin of air containments. Can be point (coming from a defined site) or non-point (coming from many diffuse sources). Stationary sources include relatively large, fixed facilities such as power plants, chemical process industries, and petroleum refineries.
Southwest Washington Regional Transportation Council (RTC)	The regional transportation planning agency for Southwest Washington (MPO/RTPO).
Sprawl	Urban form that connotatively depicts the movement of people from the central city to the suburbs. Concerns associated with sprawl include loss of farmland and open space due to low-density land development, increased public service costs, and environmental degradation as well as other concerns associated with transportation.
Stakeholders	Individuals and organizations involved in or affected by the transportation planning process. Include federal/state/local officials, MPO's, transit operators, freight companies, shippers, and the general public.
State Implementation Plan (SIP)	Produced by the state environmental agency, not the MPO. Contains specific strategies for controlling emissions and reducing ambient levels of pollutants, in order to satisfy Clear Air Act (CAA) requirements for demonstrations of reasonable further progress toward attainment. Mostly taken into account in the transportation planning process.
State Planning And Research Funds (SP&R)	Primary source of funding for statewide long-range planning.
State Transportation Improvement Program (STIP)	A staged, multi-year, statewide, intermodal program of transportation projects, consistent with the statewide transportation plan and planning processes as well as metropolitan plans, TIP's and processes.
Surface Transportation Program (STP)	Federal-aid highway funding program that funds a broad range of surface transportation capital needs, including many roads, transit, sea and airport access, vanpool, bike, and pedestrian facilities.
TDM	Transportation Management (TDM) is a demand-based technique for reducing traffic congestion, such as ride-sharing programs and flexible work schedules enabling employees to commute to and from work outside of peak hours.
TEA-21	(see Transportation Equity Act for the 21st Century)
Telecommuting	Communicating electronically (by telephone, computer, fax, etc.) with an office, either from home or another site, instead of travelling to it physically.
TIF	Transportation Impact Fee. TIF is the traffic impact component of a development impact fee. An impact fee is a fee levied on a developer by the county as compensation for expected effects of the development.
TIP	Six-Year Transportation Improvement Program.
Title VI	Title VI of the Civil Rights Act of 1964. Prohibits discrimination in any program receiving federal assistance.
Traffic Calming	Using a variety of techniques, a method of altering or designing a street to encourage slower driving.
Transportation Control Measures (TCM)	Specific measures that reduce emissions by either reducing vehicle use or reducing traffic flow. Examples: improved public transit, high-occupancy vehicle lanes, shared-ride services, bicycle/pedestrian facilities, and flexible work schedules.
Transportation Demand Management (TDM)	Measures which try to reduce the proportion of person-trips traveling by Single Occupant Vehicle (SOV). They can include promotion of non-SOV modes of transportation, car and vanpool formation assistance, transit subsidies, and a variety of other measures.
Transportation Equity Act for the 21st Century (TEA-21)	Federal law passed in 1998, provides state and local transportation planners and decision-makers with the flexibility to fund transportation projects, which best meet locally determined goals and objectives for mobility, economic opportunity, and air quality. TEA-21 allows for the flexible use, with some restrictions, of selected traditional Federal Highway and Transit funding sources.
Transportation Improvement Program (TIP)	Also known as the Metropolitan Transportation Improvement Program (MTIP), the TIP is a three-year transportation investment strategy required under ISTEA and TEA-21, similar to the six-year TIPs required of local jurisdictions by state law, which addresses the goals of long-range plans and lists priority projects and activities for the region. The MTIP includes projects within the MPO's area that are proposed for funding.
Transportation Management Area (TMA)	All urbanized areas over 200,000 in population, and any other area that requests such designation.
Transportation Systems Management (TSM)	TSM represents the best that can be done for mobility with existing infrastructure - that is, without construction of a new or widened highway or without construction of a new transit guideway. Generally, the TSM alternative emphasizes upgrades in transit service through operational and small physical improvements, plus selected highway upgrades through intersection improvements, traffic signal improvements, minor widening, and other focused traffic engineering actions.
Tri-Met or Tri-County Metropolitan Transportation district	The transit agency serving most of Clackamas, Multnomah, and Washington Counties (Oregon).
Trust Fund	A fund created with receipts that are held in trust by the government earmarked by law for use in carrying out specific purposes and programs in accordance with an agreement or a statute.
Unified Planning Work Program (UPWP)	The management plan for the (metropolitan) planning program. Its purpose is to coordinate the planning activities of all participants in the planning process.
Urban Growth Boundary (UGB)	The boundary around a metropolitan area known as the Urban Growth Area (UGA) outside of which no urban improvements may occur. The UGB is intended to accommodate all projected population and employment growth within a 20-year planning period.
Urbanized Area	Area that contains a city of 50,000 or more population plus incorporated surrounding areas meeting size or density criteria as defined by the U.S. Census.
V/C Ratio	The theoretical ratio of traffic volume on to carrying capacity for a given roadway. When identified, a V/C ratio below "1" means that traffic volumes are below the capacity of the roadway. When identified as greater than "1", the traffic volume has theoretically exceeded the carrying capacity of the roadway.
Volume	The number of vehicles passing a point on a lane or roadway during some time interval, often taken to be one hour, but may also be expressed in terms such as sub-hourly, daily, or annually.
Washington State Department of Transportation (WSDOT)	A department of the State of Washington responsible for transportation-related planning, management, and coordination.