GLOSSARY and ACRONYMS

Access Control- The act of controlling access to specific highways by acquiring rights of access from abutting property owners and selectively limiting approaches to the highway in order to preserve the highway’s safety and efficiency.

Access Management- The controlling or managing of access along arterial roadways for the purpose of improving average travel speeds and increasing the capacity of the road, thereby improving mobility.  Access management strategies include the following:

• Physical restrictions of left turns (raised medians)

• Restricting curb cuts and direct access driveways

• Elimination of parking on the arterial

• Locating intersections at no less than minimum intervals

• Construction of frontage roads to collect local business traffic and funnel it to nearby intersections.

Activity Center- A physical area characterized by concentrated activity.  The area may include one type of activity, such as a large retail center, or many varied activities, such as a mixed-use development. 

Adequate Facilities Ordinance- An ordinance that requires a determination that there will be adequate public facilities available to support a development before the development is approved.

Ambient Air- The surrounding air (excluding indoor air).

American Association of State & Highway Transportation Officials (AASHTO)- A nonprofit, nonpartisan association representing highway and transportation departments in the 50 states, the District of Columbia and Puerto Rico.

Americans with Disabilities Act (ADA)- Federal legislation requiring the provision of facilities to individuals with disabilities that will assure accessibility to all transportation facilities both public and private.

Arterial- Signalized streets that serve primarily through-traffic and provide access to abutting properties as a secondary function.

Arterial Class- A categorization of arterials involving functional and design categories and free-flow speed.

Asphalt Concrete Pavement (ACP)- A pavement surface consisting of plant-mixed asphalt oils and aggregate.

At-Grade Intersection- An intersection of two or more roads and/or highways where traffic movement is controlled by traffic signs or signals. 

Average Daily Traffic (ADT)- The total volume (both directions) that traveled over a highway segment during a one year period divided by the number of days in the year.

Average Stopped-Time Delay- The total time vehicles are stopped in an intersection approach or lane group during a specified time interval divided by the volume departing from the approach or lane group during the same time period, in seconds per vehicle.

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Bicycle Advisory Board (BAB)- Established to provide advice and direction to the city council and all departments and offices of the City on matters relating to bicycling and to raise public awareness of bicycling issues.

Barrier-Separated Facility- HOV lane that is physically separated from adjacent mixed flow freeway lanes.

Benefit/Cost (B/C)- A formula for prioritizing highway improvement projects.  A projects B/C is calculated by compiling all measurable benefits and dividing by all measurable costs over a specific time period, typically 20 years.

Bike Lane- A portion of a roadway that has been designated by striping, signing and pavement markings for the preferential or exclusive use of bicycles.

Bike Path- A bikeway physically separated from motorized traffic by an open space or barrier, either within the highway right-of-way or within an independent right-of-way.

Bikeway- Any road, path or way, which in some manner is specifically designated as being open to bicycle travel, regardless of whether such facilities are designated for the exclusive use of bicyclists or are to be shared with other vehicles.

Bituminous Surface Treatment (BST)- A pavement surface constructed by applying liquid asphalt directly on roadway followed immediately by a layer of crushed aggregate.

Bus Lane- A lane restricted to usage by buses by special regulations and markings.

Busway- A preferential roadway or ramp designed for exclusive use by buses, located either in separate right of way or within the freeway corridor. 

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CAL3QHC & CAL3QHCR- Air quality modeling software for intersection analysis.

Capacity- The maximum rate of flow at which persons or 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 or persons per hour.

Capital Costs- The costs of long-term assets of a public transit system such as property, buildings and vehicles.

Carbon Monoxide (CO)- A colorless, poisonous gas gormed when carbon-containing fuel is not burned completely. 

Census Block (CB)- A subdivision of a census tract, a block is the smallest geographic unit for which the Census Bureau tabulates 100-percent data. Many blocks correspond to individual city blocks bounded by streets, but blocks -- especially in rural areas - may include many square miles and may have some boundaries that are not streets.

Census Tract (CT)- Small, relatively permanent statistical subdivisions of a county. Census tracts are delineated for most metropolitan areas and other densely populated counties by local census statistical areas committees following Census Bureau guidelines.

Central Business District (CBD)- a commercial heart of a city, such as a city center or downtown area.

Channelization- The separation or regulation of conflicting traffic movements into defined lanes of travel to provide safe and efficient movement of vehicles and pedestrians.

Clean Air Act (CAA)- The comprehensive Federal law that regulates air emissions from area, stationary, and mobile sources.

Collector Street- Surface streets providing land access and traffic circulation service within residential, commercial and industrial areas.

Community Development Block Grant (CDBG)- Program that funds activities which address affordable housing, public facility, infrastructure, economic development, public services, and other needs of low-income persons throughout Spokane County.

Commute Trip Reduction- State law requiring employers of 100 or more people to reduce the number of single-occupancy vehicle trips to their work site.

Comprehensive Plan- A generalized coordinated land use policy statement of the governing body of a county or city that is adopted pursuant to the Growth Management Program.

Concurrency- A term used in the Growth Management Act that describes the requirement that supporting infrastructure must be in place or ‘concurrent with the development’ to accommodate transportation impacts, or a financial commitment is in place to provide the improvements or strategies within six years.

Congestion Mitigation and Air Quality Improvement Program (CMAQ)- A flexible funding program administered by the Federal Highway Administration that obligates funds to projects and programs that reduce harmful vehicle emissions.

Critical Areas- As a key part in managing growth in Washington, the Growth Management Program requires that eAvery county and city classify and designate critical areas: wetlands, aquifer recharge areas, fish and wildlife habitat, frequently flooded areas, geologically hazardous areas and rare/endangered plant habitat.

Cycle Length- The total time for a traffic signal to complete a sequence of signal indications.

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Design Analysis- A usage of capacity analysis procedures to determine the size (number of lanes) required on a given segment of a facility in order to provide a specified level of service.

Determination of Non-Significance (DNS)- A Determination of Non-Significance is the written decision by the Environmental Review Committee stating a project will have limited environmental impacts and measures needed to be taken to reduce these impacts.

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Emissions Budget (for CO)- Establishes a limit as to total CO emissions allowable by on road mobile sources in the Spokane non-attainment area.

EMME/2- Regional Travel Demand Modeling software.

Environmental Impact Statement (EIS)- A detailed report of potential environmental and societal impacts resulting from various alternatives for a roadway improvement.

Environmental Protection Agency- A federal agency responsible for environmental concerns.

Employee Transportation Coordinator (ETC)- A representative of an organization or company who has been chosen or volunteered to promote alternative transportation within that organization or company.

Expressway- A divided arterial highway for through traffic with full or partial control of access and generally with grade separations at intersections.

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Federal Highway Administration (FHWA)- Arm of the United State Department of Transportation that is responsible for administering all federal-aid highway funds and programs.

Federal Transit Administration- Arm of the U.S. Department of Transportation.  Regulates and helps fund all public transportation within local communities.

Freeway- A divided arterial highway designed for the safe non-impeded movement of large volumes of traffic, with full control of access and grade separations at intersections.

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Geographic Information System (GIS)- A computerized geographic data storage analysis and display system.  GIS allows the assignment of multiple ‘layers’ of data sets to the map of a given area. 

Grade Separation- The raising or lowering of a road or highway grade to bridge over/under another road or highway to eliminate traffic movement conflicts.

Growth Management Act- Addresses the negative consequences of unprecedented population growth and suburban sprawl in Washington and requires cities and towns to develop a plan as to how to deal with that sprawl.

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High Capacity Transit- A public transit system, such as rail, that can accommodate large volumes of riders.

High Occupancy Vehicle (HOV)- A vehicle carrying enough people to be eligible to travel in lanes designated for use by carpools, vanpools and buses.

Highway/Transit Assignment- The fifth and final step in travel forecasting.  A forecast of the highway route or transit route a trip will traverse.  Highway/transit assignment simulates the traffic volumes and transit ridership on the highway and transit system.

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I/C- Interchange

Infrastructure- The essential elements of a structure, system, plan of operations, etc.

Intelligent Transportation System (ITS)- Generally refers to the application of advanced electronics and computer technology to automate highway and vehicle systems to enable more efficient and safer use of existing highways.

Inter-local Agreement- An agreement among the jurisdictions within a Regional Transportation Planning Organization (RTPO) that establishes the organization and defines duties and relationships for member counties.  The agreement governs RTPO operations and is submitted as part of the RTPO’s designation package.

Intermodal- Refers to transfer facilities where freight or passengers change modes of transport.  For example, an airport is an intermodal facility where freight and passengers make intermodal transfers between motorized vehicles and airplanes.

Interstate Safety Matrix- Interstate highway Design Manual guidelines for roadway geometric and roadside elements.

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Land Use Assumptions- The existing and proposed land uses, i.e. retail, various residential densities, office, manufacturing, etc. used in developing travel forecasts.  Housing units and employment numbers in the travel forecasting process represents these land uses.

Level of Service (LOS)- A gauge for evaluating the quality of service on the transportation system.  Described by travel times, freedom to maneuver, traffic interruptions, comfort, convenience and safety.

Link Concurrency Management System- A gauge for evaluating the quality of service on the transportation system.  Described by travel times, freedom to maneuver, traffic interruptions, comfort, convenience and safety.

Local Improvement District (LID)- A City of Spokane program that helps pay for improvements such as streetlights, street and alley paving and water and sewage systems.

LRT- Light rail transit

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Metropolitan Area Boundary (MAB)- An area determined by an agreement between the governor and the MPO as defined in (23 USC 134).

Mitigated Determination of Non-Significance- The written decision by the Environmental Review Committee stating a project will have limited environmental impacts and measures need to be taken to reduce these impacts.

MPO (Metropolitan Planning Organization)- A planning organization that is required by federal regulation in all urban areas with a population of over 50,000.  The MPO coordinates transportation and land use planning within its designated region.

Metropolitan Transportation Plan (MTP)- A product of the regional transportation planning process.  It guides the improvement of the regional transportation system.  Identifies and addresses regional transportation issues. 

MOBILE5a and MOBILE5ah- Regional Air Quality Modeling software for emissions analysis.

Model- A set of mathematical formulae that expresses the actions and interactions of the elements of a system in such a manner that the system may be evaluated under any given set of conditions, i.e., land-use, economic, socioeconomic and travel characteristics.

Multimodal- Refers to a plan or program that accounts for the needs and/or trends of multiple modes.

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National Environmental Policy Act (NEPA)- An Act to establish a national policy for the environment, to provide for the establishment of a Council on Environmental Quality and for other purposes.

Nitrogen Dioxide (NO₂)- A gas and strong oxidizing agent that is one of the major components of acid rain and smog.

Non-attainment Area- An area designated by EPA in which National Ambient Air Quality Standards are exceeded.

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Office of Financial Management (OFM)- Provides vital information, fiscal services and policy support that the Governor, legislature and state agencies need to serve the people of Washington State.

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Particulate Matter (PM-10)- Tiny airborne particles resulting from wood stove burning, outdoor burning, road dust and industry which can get in lungs and impair the respiratory system.

Peak-Hour Factor- The hourly volume during the maximum volume hour of the day divided by the peak 15 minute rate of flow within the peak hour.

Planned Unit Development (PUD)- Planned Unit Developments consist of residential buildings clustered or laid out with reduced setbacks, if amenities such as adequate open spaces and other design provisions are provided.

Planning Analysis- A use of capacity analysis procedures to estimate the number of lanes required by a facility in order to provide for a specified level of service based on approximate and general planning date in the early stages of project development.

PM_2.5- Particulate matter such as dust, dirt, soot or smoke found in the air that are smaller than 2.5 micrometers (100 times thinner than a human hair).

PM₁₀- Particulate matter such as dust, dirt soot or smoke found in the air that are between 2.5 and 10 micrometers (from about 25 to 100 times thinner than a human hair).

Point Source- Identifiable pollution sources such as large industries that emit significant levels of air pollutants in a particulate geographic location.

Portland Cement Concrete Pavement (PCCP)- A pavement surface consisting of plant-mixed concrete using Portland cement and aggregate.

Preliminary Engineering (PE)- All work needed to allow for construction including construction plans, specifications and cost estimates for transportation facilities. 

Programmed Project- A project that has expenditures planned within a specific program of the Washington State Department of Transportation’s approved biennial budget.

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Regional Development Strategy- The Regional Transportation Plan must contain an explicit statement defining the regional development strategy, which is a generalized scheme of existing and proposed land use that serves as the basis for transportation planning.

Right Of Way (ROW)- An easement that permits one to travel across the real property of another, or the strip of land subject to such an easement.

Regional Transportation Planning Organization (RTPO)- A voluntary association of local governments within a region.  They are authorized under the Growth Management Act to facilitate the development of a regional transportation plan.  The RTPO coordinates transportation planning efforts of all government units within the region.

Route Development Plan (RDP)- A long-range plan for a specific highway corridor that describes existing highway conditions, local land use plans and recommends improvements and goals for future improvements and transportation services. 

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SOV- Single Occupancy Vehicle

Six-Year Plan- An implementation plan for the first six years of the Washington Transportation Plan. 

Spokane County Air Pollution Control Authority (SCAPCA)- The local agency which administers state, federal and local laws and regulations regarding air pollution control.

State Environmental Policy Act (SEPA)- State policy that requires state and local agencies to consider the likely environmental consequences of a proposal before approving or denying the proposal.

State Implementation Plan (SIP)- A plan the state adopts to ensure that state air quality objectives are met.

State Environmental Protection Act (SEPA)- Act that requires consideration of alternatives and mitigation of environmental impacts for major projects and programs both public and private.

Sulfur Dioxide (SO₂)- A gas or liquid resulting from the burning of sulfur containing fuel.

Synchro- Intersection Capacity Analysis Computer Model

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Transportation Control Measure (TCM)- TCMs are measures contained in the State Implementation Plan (SIP) that are designed to reduce vehicle related air pollution. 

Transportation Demand Management (TDM)- Action intended to modify travel behavior, usually to avoid more costly expansion of transportation system. 

Transportation Analysis Zones (TAZ)- Any area designated for a study of household travel characteristics in order to create a database of accurate information about the number of trips, trip length and trip purpose by mode and time-of-day for the area of households in question.

Transportation Improvement Program (TIP)- A multi-year funding program document that lists federally and non-federally funded transportation improvements proposed by various jurisdictions in Spokane.

Transportation Management Area (TMA)- TMA’s are MPOs over 200,000 population.  TMAs deal with more complex issues than MPOs, requiring more of an emphasis on planning.

Transportation Technical Committee (TTC)- An SRTC committee composed of professionals from local and state agencies which provides project input and helps assure a coordinated and well-considered regional transportation system.

Trip Distribution- The third step in forecasting travel is forecasting where trips begin and where they end.  This is done for different trip purposes on trip types. 

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Unsignalized Intersection- Any intersection not controlled by traffic signals.

Urban Growth Area- Areas where urban growth within is encouraged and where growth outside can occur only if it is not urban in nature.

Urbanized Area (UZA)- Urbanized Area is a Census classification for areas having populations of 5,000 or more and that meet certain population density requirements.

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V/C Ratio- The ratio of traffic volume to capacity for a traffic facility.

Volatile Organic Compounds- Unstable or carbon-based compounds that, when combined with nitrogen oxides, will produce ozone.

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Washington State Transportation Center (TRAC)- Research committee comprised of the Department of Transportation, University of Washington and Washington State University.