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Illinois Department of Transportation
Office of Intermodal Project Implementation
69 West Washington Street
Chicago, Illinois 60602



Air Quality
The cleanliness of the air; the fewer pollutants in the air, the better the air quality.

The route that an improvement, such as a rail line, could take through a corridor.

An alternative includes various improvements (modal and routing options) designed to address transportation deficiencies in the project area.

American Recovery and Reinvestment Act (ARRA)
The economic stimulus package enacted into law in February 2009.  The provisions of the act include tax cuts, healthcare, education, aid to low income workers/unemployed/retirees, infrastructure investments, supplemental investments, energy, housing, scientific research, and other grant provisions.   

The National Railroad Passenger Corporation, provides intercity rail passenger service to the general public in the US. Amtrak was incorporated in 1971 and receives annual appropriations from the federal government to operate the nationwide passenger rail system and maintain the underlying infrastructure.


The process to assess the compliance of any transportation plan, program, or project with air quality control plans. The conformity process is defined by the Clean Air Act and related amendments.

Cooperating Agencies (CA)
Per the National Environmental Policy Act (NEPA), a cooperating agency is any federal agency that has jurisdiction by law or special expertise with respect to any environmental impact involved in a proposed project.  Cooperating agencies are permitted, by request of the lead agency, to assume responsibility for developing information and preparing environmental analyses for topics about which they have special expertise.

A corridor is a general path from one point to another.


Descriptive characteristics of populations.  Examples include age, race and ethnicity, gender, income, employment, and household status.


Environmental Assessment (EA)
Concise report which evaluates the environmental effects and project-related social impacts of a project in order to evaluate their significance; it may include identifying measures to prevent, minimize, mitigate, or compensate for adverse environmental effects for which federal funding is being sought.

Environmental Impact Statement (EIS)
Report which evaluates the economic, social, and environmental effects of a major proposed project for which federal funding is being sought. Impacts could include air, water, or noise pollution; natural resources; employment effects; displacement of people or businesses; or community or regional growth impacts, among others.

Surrounding conditions or circumstances.  Usually used as a reference to nature (the natural environment), but also can include man-made conditions (the built environment).

Environmental Mitigation
Methods, strategies, or actions to reduce the negative effects (i.e., direct, indirect, and cumulative) of a transportation project on the environment.

Environmental Protection Agency (EPA)
EPA is the federal source agency of air quality control regulations affecting transportation.

Evaluation Criteria
A standard or measure that permits a comparative evaluation of an alternative.


Federal Railroad Administration (FRA)
Division of the U.S. Department of Transportation that funds rail programs.

Commercial goods carried by a vehicle, usually a train, truck, plane, or ship; cargo.


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.


High Speed Rail
Intercity passenger train service traveling at speeds of 110 mph or greater.


Illinois Commerce Commission (ICC)
A quasi-judicial tribunal which regulates public utility services in Illinois. The mission of the ICC is "to pursue an appropriate balance between the interest of consumers and existing and emerging service providers to ensure the provision of adequate, efficient, reliable, safe and least-cost public utility services."

Illinois Department of Natural Resources (IDNR)
Illinois Department of Natural Resources (IDNR) is a State Agency that manages, protects and sustains Illinois' natural and cultural resources; provides resource-compatible recreational opportunities; and  promotes natural resource-related issues for the public's safety and education.

Illinois Department of Transportation (IDOT)
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, and rail freight and rail passenger systems.

A term connoting the physical underpinnings of society at large, including, but not limited to, railroads, roads, bridges, transit, water and waste systems, public housing, sidewalks, utility installations, parks, public buildings, and communications networks.


Metra provides commuter rail service in the Chicago Metropolitan area. Metra’s system is comprised of 11 rail lines, operating over 1,100 miles of track and over 800 bridges. Metra serves the counties of Cook, DuPage, Lake, Will, McHenry, and Kane in northeastern Illinois.

The ability to move or be moved from place to place. Typically, mobility is the ease with which movement can occur between geographic areas or parts of a region.


National Ambient Air Quality Standards (NAAQS)
Federal standards that set allowable concentrations and exposure limits for various air pollutants.

National Environmental Policy Act (NEPA)
NEPA guides federally funded projects and projects that require a Federal permit to lessen potential damages to the environment. The NEPA process requires federal agencies to integrate environmental values into their decision-making process by considering the environmental impacts of their proposed actions and reasonable alternatives to these actions.  Environmental factors such as air quality, wildlife, vegetation, water quality, wetlands, geology, neighborhoods, park/recreation areas, utilities, visual quality, and cultural resources will be assessed. NEPA encourages early and frequent coordination with the public and resource agencies throughout the project development process.  Public comments that are received during the alternative analysis phase are considered in the draft environmental document. Following NEPA guidelines, a document called an Environmental Assessment will be prepared. The process calls for continuous environmental evaluations as alternatives are analyzed.


Ozone is a colorless gas with a sweet odor. Ozone is not a direct emission from transportation sources but rather a secondary pollutant formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight. Ozone is associated with smog or haze conditions. Although ozone in the upper atmosphere protects the earth from harmful ultraviolet rays, ground level ozone produces an unhealthy environment in which to live.


Participating Agencies
Any federal, state, tribal, regional, and local government agency that may have an interest in the project.  By definition, all cooperating agencies will also be considered participating agencies.  However, not all participating agencies will serve as cooperating agencies.

Particulate Matter (PM), (PM 10, PM 2.5)
Any material that exists as solid or liquid in the atmosphere. Particulate matter may be in the form of fly ash, soot, dust, fog, fumes, etc.

Positive Train Control (PTC) – A safety system that uses advanced communication systems to avoid collisions with other trains, protects maintenance workers, and enforces speeds in slow zones.

Problem Statement
A concise narrative, prepared as part of a project needs study, defining the fundamental situation or circumstance to be solved.  A problem      statement will generally describe a particular situation in which an expected level of performance is not being achieved, and will list one or more important factors which cause or contribute to the unacceptable performance.


Right-of-Way (ROW)
The land (usually a strip) acquired for or devoted to transportation purposes.

Record of Decision (ROD)
A signed Federal document representing the culmination of the federal environmental document review and approval process and documenting Federal project environmental approval.


Siding is a second/alternate track that provides passing opportunities for trains moving in the opposite-direction, as well as slower-moving same-direction trains. The use of a siding will permit the high-speed trains to maintain these higher speeds.

A term used to describe social and economic factors, generally resulting from an analysis of demographics of a population.


Transportation Network
Arrangement of transportation systems for the movement of passenger and cargo.  Transportation systems include highways, freight railroads, intercity passenger rail, public transportation, and non-motorized networks.


U.S. Department of Transportation (DOT)
The principal direct federal funding and regulating agency for transportation facilities and programs. The Federal Railroad Administration (FRA) is a unit of the U.S. DOT.


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