2012 Long Range Transportation Plan

Transforming Transportation for Tomorrow

Glossary of Terms


Access, Accessibility

The opportunity to reach a given end use within a certain time frame, or without being impeded by physical, social or economic barriers. Typically, accessibility is the extent to which transportation improvements make connections between geographic areas or portions of the region that were not previously well connected.

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 bus or light rail line, could take through a corridor.


A feasible transportation improvement that is under consideration.

Americans with Disabilities Act of 1990 (ADA)

Federal Law that requires public facilities, including transportation services, to be fully accessible for persons with disabilities.


The nation’s intercity passenger rail system.  Amtrak is the brand name of the National Railroad Passenger Corporation, a quasi-governmental agency created in 1971.


A major street, primarily for through traffic, usually with unlimited access to adjacent streets.

Average Daily Traffic (ADT)

The total volume of traffic in both directions on a highway during a time period of greater than one day but less than a year, then divided by the number of days for which traffic data were collected.


Bus Rapid Transit (BRT)

Public transportation systems consisting of rubber-tired bus vehicles operating on dedicated right-of-way or lanes of existing roadways reserved exclusively for bus transit. Bus vehicle design can vary, including articulated buses for high demand, and can be diesel, gasoline or alternative fuel powered. BRT typically serves urban and suburban areas with traffic signal priority and station platforms, usually 0.25 to 2 miles apart.



The maximum amount of traffic on any transportation facility that can be accommodated and still function.


A road that collects and distributes traffic. Sometimes built next to an expressway to collect traffic from the area and then funnel it onto the expressway. Generally fewer lanes than an arterial.

Commuter Rail

High capacity public transportation systems consisting of electric or diesel propelled train sets usually operating in right-of-way at ground level or an embankment. Commuter rail typically operates between a central city and its suburbs with station spacing generally 2 - 5 miles apart.

Complete Streets

The design of roadways to safely and comfortably provide for the needs of all users, including, but not limited to, motorists, cyclists, pedestrians, transit passengers, school bus riders, commercial goods movement, persons with disabilities, seniors, and emergency users.


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.

Congested Vehicle Miles of Travel

This measure indicates how many vehicle miles are traveled over the threshold for congestion conditions. If there is no congestion, then Congested VMT would be zero, however if traffic builds beyond the limit for congestion, then this measure would report the difference, or the amount causing the congestion.

Congestion Management System (CMS)

A plan developed by a Transportation Management Area (TMA) that provides for effective management of new and existing transportation facilities through the use of travel demand reduction and operational management strategies.

Containerized Cargo

Cargo is commercial goods that are being transported. Containers are standard-size, metal boxes that carry cargo and can be moved between modes, like between a ship, railcar or truck. Container on Flatcar (COFC) and Trailer on Flatcar (TOFC) are containers or truck trailers that sit on and are transported by flatbed railcars.

Context Sensitive Solutions (CSS), IDOT program

An interdisciplinary approach that seeks effective, multimodal transportation solutions by working with stakeholders to develop, build and maintain cost-effective transportation facilities which fit into and reflect the project's scenic, economic, historic, and natural surroundings.



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


The place where a trip ends.



Surrounding conditions or circumstances, including both the natural and built environment.

Environmental Justice

An Executive Order requiring to the greatest extent possible allowed by law, administer and implement its federal programs, policies, and activities that affect human health or the environment so as to identify and avoid disproportionately high and adverse effects on minority and low-income populations.

Environmental Mitigation

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


A controlled-access, divided highway for through traffic. Intersections with other roads are separated by different road levels.


Federal Aviation Administration (FAA)

Division of the U.S. Department of Transportation that oversees and funds aviation planning and programs.

Federal Highway Administration (FHWA)

Division of the U.S. Department of Transportation that oversees and funds highway planning and programs.

Federal Railroad Administration (FRA)

Division of the U.S. Department of Transportation that oversees and funds railroad planning and programs.

Federal Transit Administration (FTA)

Division of the U.S. Department of Transportation that oversees and funds transit planning and programs.


A controlled-access, divided highway for through traffic. Intersections with other roads are separated by different road levels.


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


A calculation or estimate of future conditions.

Functional Classification

A method of cataloging a road’s purpose and design. Roads are generally classified as Interstates, Freeways / Expressways, Arterials (principal or minor, urban or non-urban), Collectors (major or minor, urban or non-urban), and local roads (urban or non-urban).


Heavy Rail Transit (HRT)

Public transportation system consisting of steel wheeled, high performance electric powered rail vehicles operating in train sets. HRT usually operates in a right-of-way that is fully grade separated (elevated, trench, or subway) and serves denser urban areas with station spacing generally 1 mile apart.


Term used to describe higher capacity roads; also includes rights of way, bridges, railroad crossings, tunnels, drainage structures, signs, guardrails, and protective structures in connection with highways.

High Occupancy Toll (HOT)

High Occupancy Toll is a road pricing scheme that allows lower occupancy vehicles to gain access to High Occupancy Vehicle (HOV) Lanes by paying a toll.

High Occupancy Vehicle (HOV)

HOV is an acronym for High Occupancy Vehicle and is typically used in association with travel lanes dedicated to a vehicle with a specified number of occupants being 2 or greater.

Human Capital

The skills, competencies, and knowledge embodied in the ability to perform work that produces economic value.

Human Services Transportation Plan

A coordinated plan for transit service delivery developed with transportation and human service providers that addresses the needs of individuals with disabilities, older adults, and low-income individuals, and that prioritizes transportation services for funding and implementation.


IDOT Division of Aeronautics

Responsible for coordinating and implementing programs concerning air safety, airport construction and other aeronautical activities throughout the state. The Division operates the state owned executive air service, and it cooperates with local law enforcement and other agencies throughout the state to provide emergency or disaster related air service as needed using the state fleet of utility aircraft.

IDOT Division of Highways

The Division of Highways is responsible for planning, designing, constructing, operating and maintaining a safe highway system that links the state together. They also work with local governments to ensure that the system accommodates local community development priorities and respects the needs of alternative local modes of transportation.

IDOT Division of Public and Intermodal Transportation

The Division of Public and Intermodal Transportation develops, implements, and advocates for policies and practices that promote safe, efficient, affordable, reliable, and coordinated mass and rail transit.

IDOT Division of Traffic Safety

This division is responsible for highway safety activities and compiles crash data and evaluates and analyzes the information to identify highway improvements in problem areas.

IDOT Office of Planning and Programming

This office is responsible for managing the planning and programming of the state’s transportation system. Planning activities include the State Transportation Plan, coordinating with the 14 metropolitan planning organizations and working with the non-metropolitan areas in addressing the state’s transportation needs.


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

Intelligent Transportation Systems (ITS)

The collection, storage, processing, and distribution of information relating to the movement of people and goods, including systems for traffic management, public transportation management, emergency management, traveler information, advanced vehicle control and safety, commercial vehicle operations, electronic payment, and railroad grade crossing safety.

Interstate System

The system of highways that connects the principal metropolitan areas, cities, and industrial centers of the United States. The Interstate System also connects the US to internationally significant routes in Mexico and Canada. The routes of the Interstate System are selected jointly by the state department of transportation for each state and the adjoining states, subject to the approval of the US Secretary of Transportation.


Land Use

Refers to how land and the structures (development) on it are used, i.e., commercial, residential, retail, industrial, etc.

Light Rail Transit (LRT)

High capacity public transportation systems consisting of steel wheeled electric powered rail vehicles operating in train sets. LRT can operate in right-of-way that is grade separated or can operate in mixed traffic (street running). Typically serves urban and dense suburban areas with station spacing generally 1 mile apart.

Level of Service (LOS)

A qualitative measure describing operational conditions and the perception of transportation users of the existing conditions. Generally using six levels of service ranging from A to F, with level of service A representing the best operating conditions and level of service F the worst. Initially used to define the road network, the concept has been expanded to include bicycle and pedestrian conditions.

Local Street

A low-volume, high-access road intended solely for access to adjacent properties.

Long Range Transportation Plan (LRTP)

A transportation plan typically covering a twenty-year plus timeframe that includes policies and/or planned major transportation improvements.


Major Investment

A “high-type highway or transit improvement of substantial cost that is expected to have a significant effect on capacity, traffic, level of service or mode share at the transportation corridor or sub-area scale.”

Managed Lanes

Highway facilities or a set of lanes where operational strategies are proactively implemented.  These operational strategies can include pricing (tolls, congestion pricing), vehicle eligibility (carpools and buses), and/or access control (express or reversible lanes).

Metropolitan Planning Organization (MPO)

Formed in cooperation with the state, the Metropolitan Planning Organization (MPO) develops long range transportation plans and transportation improvement programs for metropolitan area greater than 50,000 in population.

Metropolitan Statistical Area (MSA)

Census Bureau delineation for major metro areas in the U.S. Also includes standard (SMSA) and consolidated metropolitan statistical area (CMSA).


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 the region.

Mode, Intermodal, Multimodal

Forms of transportation, such as personal motorized vehicle, public transit, bicycling and walking. Intermodal refers to the connections between modes, and multi-modal refers to the availability of transportation options within a system or corridor.


National Environmental Policy Act (NEPA)

The federal law that requires the preparation of an Environmental Impact Statement (EIS), Environmental Assessment (EA), or Categorical Exclusion (CE).


A graphic and/or mathematical representation of multimodal paths in a transportation system.


Non-motorized transportation, also known as active transportation and human powered transportation, includes walking and bicycling, as well as small-wheeled transport (skates, skateboards, push scooters and hand carts) and wheelchair travel.


Operations, Operational Strategies

How a transportation network functions; operational strategies are techniques that influence how a network functions. For example, traffic signals and signs are operational activities that control traffic.


Paratransit, Demand Responsive or Dial-a-Ride

A service generally provided for the disabled or elderly which provides trips in response to customer calls.  Generally, not a scheduled fixed-route service.

Peak Period

The time period, usually in the morning and afternoon, when demand for transportation is high.

Policy Factors

Eight policy factors required for consideration in the development of a Long Range Transportation Plan:

  • Safety for all transportation users.
  • Preserving and managing the existing infrastructure.
  • Accommodating future growth in population and employment.
  • Support of global economic competitiveness.
  • Transportation for underserved populations such as the elderly, low-income and the persons with disabilities.
  • Protecting the environment.
  • Securing adequate funding for maintaining and improving the transportation systems.
  • Security to ensure the continued operation of the system.


A place or area usually on a waterway for loading or unloading freight. Sometimes other locations such as airports have a ‘port’ designation for commercial freight activity.

Public Participation

The active and meaningful involvement of the public in the development of transportation plans and improvement programs.

Public Private Partnerships (P3)

A contractual agreement between a public agency (federal, state or local) and a private sector entity in which the skills and assets of each sector (public and private) are shared in delivering a service or facility for the use of the general public.  Each party also shares the risks and rewards potential in the delivery of the service and/or facility.

Public Road

Any road or street under the jurisdiction of and maintained by a public authority and open to public traffic.

Public Transit (or Transportation)

Generally refers to passenger service provided to the general public along established routes with fixed or variable schedules at published fares. Related terms include transit, mass transit, public transportation or paratransit. Transit modes include commuter rail, heavy or light transit, bus, or other vehicles designated for commercial transportation of non-related persons.


Quality of Life

A term used to describe the lifestyle conditions of an area. Conditions include the scale and depth of opportunities or choices in housing, employment, transportation, the natural environment, education, health care, and recreational and entertainment activities.


Single Occupant Vehicle (SOV)

A SOV is a vehicle that carries only one occupant (the driver) to a destination.


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

Stakeholder Involvement Plan (SIP)

The SIP is a blueprint for defining methods and tools to educate and engage all stakeholders in the decision-making process for a project. The SIP provides the framework for achieving consensus and communicating the decision-making process between the general public, public agencies, and governmental officials to identify transportation solutions for the project.

Stakeholder Involvement

A process that will facilitate effective identification and understanding of the (SIP) concerns and values of all stakeholders as an integral part of the project development process. It includes a formal written plan explaining how public input and comments will be obtained.


Address present and future needs while not harming the natural resources and unique human-environmental systems, including air, water, land, energy, and human ecology and/or those of other sustainable systems.


Transportation (or Travel) Demand Management (TDM)

Strategies and collective efforts designed to achieve reductions in vehicular travel demand. In general, TDM does not require major capital improvements. It includes ridesharing, land use policies, employer-based measures, and pricing/subsidy policies.

Transportation Improvement Program (TIP)

This is a document prepared by states and MPOs citing projects to be funded under federal transportation programs, typically for a three to five year period. Without TIP inclusion, a project is ineligible for federal funding.

Travel Time

Customarily calculated as the time it takes to travel from “door-to- door.” In transportation planning, the measures of travel time include time spent accessing, waiting, and transferring between vehicles as well as time spent traveling.


Generally refers to passenger service provided to the general public along established routes with fixed or variable schedules at published fares. Related terms include public transit, mass transit, public transportation or paratransit. Transit modes include commuter rail, heavy or light transit, bus, or other vehicles designated for commercial transportation of non-related persons.

Transit Dependent

Persons who must rely on public transit or paratransit services for most of their transportation. Typically refers to individuals without access to a personal vehicle.

Transit Oriented Development (TOD)

The development of compact, mixed use, walkable communities centered around high quality transit systems/stations.


Urbanized Area

Area that contains a city of 50,000 or more population plus incorporated surrounding areas meeting set size or density criteria.

U.S. Department of Transportation (DOT)

The principal direct federal funding and regulating agency for transportation facilities and programs. FHWA and FTA and units of the US DOT.


Vehicle Hours of Travel (VHT)

The sum of time all vehicles spend traveling, calculated most typically over a 24-hour period. This statistic is most commonly summed over some area like county but can also be calculated for specific routes or trip purposes like work.

Vehicle Miles of Travel (VMT)

A standard area-wide measure of travel activity. The most conventional VMT calculation is to multiply the average length of trip by the total number of trips.


Waterway, Navigable

A river, canal or other body of water that allows for navigation of vessels

Further definitions can be found in the Transportation Dictionary sponsored by the Bureau of Transportation Statistics, at http://ntl.bts.gov/reference_shelf.html








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