GlossaryA B C D E F G I L M P R T V
An alternative includes various improvements designed to address transportation issues in the project area.
An arterial roadway serves major traffic movements or major traffic corridors. While they may provide access to abutting land, their primary function is to serve traffic moving through the area.
When two or more transportation movements intersect at the same elevation, it is referred to as an at-grade crossing. (For example, a railroad track intersecting a road or two highways that meet).
Average daily traffic (ADT)
The average 24-hour traffic volume, where the total volume during a stated period is divided by the number of days in that period. Unless otherwise stated, the period is a year. The term is commonly abbreviated as ADT.
Bi-State Regional Planning Commission (MPO)
Bi-State Regional Planning Commission (Bi-State) is a local, voluntary organization consisting of five counties and 45 municipalities. Bi-State was created in 1966 through the merger of the Scott County (IA) Metropolitan Planning Commission and the Rock Island County (IL) Regional Planning Commission. Bi-State is responsible for regional transportation planning activities.
A corridor is a general path from one point to another.
DEIS is an acronym for Draft Environmental Impact Statement. The DEIS is a federally–mandated document for projects that involve federal funding or actions. The document discloses the potential environmental impacts of the project alternatives.
EIS is an acronym for Environmental Impact Statement. The EIS is a federally-mandated document for projects that involve federal funding options or actions. The document discloses the potential environmental impacts of project alternatives.
A standard or measure that permits a comparative evaluation of an alternative.
Federal Highway Administration (FHWA)
The FHWA became a component of the U.S. Department of Transportation in 1967 pursuant to the Department of Transportation Act (49 U.S.C. app. 1651 note). It administers the highway transportation programs of the U.S. Department of Transportation under pertinent legislation and provisions of law cited in section 6a of the act (49 U.S.C. 104). The Administration encompasses highway transportation in its broadest scope seeking to coordinate highways with other modes of transportation to achieve the most effective balance of transportation systems and facilities under cohesive federal transportation policies pursuant to the act. The FHWA administers the federal-aid highway program; is responsible for several highway-related safety programs; authorized to establish and maintain a national highway network for trucks; administers a coordinated federal lands program; coordinates varied research, development and technology transfer activities; supports and participates in efforts to fund research and technology abroad; plus a few additional programs.
FEIS is an acronym for Final Environmental Impact Statement. See EIS for more information.
A full access-controlled, divided highway.
Geographic information systems (GIS)
A computer software tool that is used to solve problems based on geographically-related information. It is a system linked to a graphics system capable of collecting, storing, analyzing, and manipulating spatial information.
When two transportation movements intersect at different elevations (for example, a highway crossing over a railroad or a highway intersecting a local road when one of the roadways is carried over the other on a bridge).
Illinois Department of Transportation (Illinois DOT)
The Illinois Department of Transportation has responsibility for planning, construction and maintenance of Illinois' extensive transportation network. This network encompasses highways, bridges, airports, public transit, rail freight and rail passenger systems.
Iowa Department of Transportation (Iowa DOT)
The Iowa Department of Transportation has responsibility for planning, construction and maintenance of Iowa's extensive transportation network. This network encompasses highways, bridges, airports, public transit, trails, rail freight and rail passenger systems.
A multilevel highway intersection arranged so that vehicles may move from one road to another without crossing streams of traffic. (Webster)
A point at which separate roadways meet.
Land use forecasts
Land use forecasts are often prepared with computerized urban growth models. These models are rigorous mathematical procedures that identify the total growth of the area according to criteria that affect development decisions. Several factors are considered in these development decisions, including:
- the amount of developable land (or redevelopment) available
- policy limitations on development intensity
- the potential for utility services such as water and sewer
- proximity to residential and employment centers
Metropolitan planning organization (MPO)
Formed in cooperation with the state, the Metropolitan Planning Organization (MPO) develops transportation plans and programs for the metropolitan area. For each urbanized area, an MPO must be designated by agreement between the governor and local units of government representing 75 percent of the affected population (in the metropolitan area), including the central cities or cities as defined by the U.S. Bureau of the Census, or in accordance with procedures established by applicable state or local law.
Peak travel period
The period in the morning (a.m. peak period) and afternoon or evening (p.m. peak period) when additional transportation services are needed to handle higher traffic volumes. The period begins when normal travel volumes are increased and ends when travel volumes return to normal. In the Quad Cities, the a.m. peak period is generally 6 a.m. to 8 a.m. and the p.m. peak period is 4 p.m. to 6 p.m. weekdays.
Passenger transportation services, usually local in scope, that are available to any person who pays a prescribed fare. Public transit operates on established schedules along designated routes or lines with specific stops and is designed to move relatively large numbers of people at one time.
The land acquired by a governmental agency for transportation purposes.
Traffic control systems are designed to reduce travel times, delays and stops, while also improving the average speed on arterial roadways and freeways. These systems include elements such as coordinated traffic signals, timing plans, use of bus-priority signal control systems, and implementation of computer-based traffic control and freeway traffic management.
Transportation system management
Current transportation management practices are fundamental traffic engineering actions taken to improve the operation of the highway system. Actions are usually categorized as "supply-side" (actions intended to increase the existing vehicle capacity on the system) and "demand-side" (actions that are designed to reduce vehicle demand on the system by increasing vehicle occupancy). For example:
- traffic engineering improvements: left- and right-turn lanes, one-way streets, bus turn outside lanes
- traffic control improvements: traffic signal interconnection, use of bus-priority signal control
Vehicle miles traveled (VMT)
A measure frequently used by transportation planners. A vehicle mile represents one vehicle traveling for one mile.