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abandon
A proceeding wherein a shipper/consignee seeks authority to abandon all or parts of their cargo; railroad abandonment occurs when operation of all or part of a route or services is ceased, especially with the intent of never resuming it again; abandonment of an easement is the relinquishment of some accommodation or right in another's land, such as right of way.
abutment
A substructure element supporting each end of a single span or the extreme ends of a multispan superstructure and, in general, retaining or supporting the approach embankment.
acceleration lane
Drivers entering a roadway use this lane to increase speed so that they may safely merge with traffic.
access management
Measures regulating access to streets, roads and highways from public roads and private driveways.
accessibility
The extent to which facilities accommodate persons with disabilities, including wheelchair users.
Accident Location and Analysis System (ALAS)
Computerized information available to engineering and law enforcement agencies.
active warning device
Flashing lights and/or gates used at railroad-highway grade crossings.
administrative law judge
A representative of a government commission or agency vested with power to administer oaths, examine witnesses, take testimony and conduct hearings of cases submitted to, or initiated by, that agency.
advance acquisition
The acquisition of real property rights for use on a transportation corridor in advance of the fiscal year in which right of way acquisition would normally occur; this is done to take advantage of favorable prices or the availability of land and to preclude further development that would make the property more costly to the public.
alignment
The horizontal and vertical definition of a roadway.
all-terrain vehicles (ATV)
Vehicle designed for off-road use.
alternate mode users
Individuals who choose a method of transportation other than driving a single-occupancy motor vehicle.
alternative transportation mode
This term refers to all passenger modes of travel except for single-occupancy vehicles, including bicycling, walking, public transportation, carpooling and vanpooling.
ambient conditions
The visual background or surrounding atmospheric and visibility conditions.
Americans with Disabilities Act of 1990 (ADA)
Civil rights legislation enacted in 1990 to end discrimination against persons with disabilities.
anchor span
The span that counterbalances and holds in equilibrium the cantilevered portion of an adjacent bridge span during construction.
anchorage
Massive concrete structural parts of a bridge, also called "cable anchorages" and "shore anchors," these are placed far enough back from the edge of the water to ensure against sliding; they provide stability where the cable end is tied, withstanding the tremendous stress of the loaded cables.
angular motion sensitivity
The ability of an observer to detect changes in the apparent distance and direction of movement of an object as a function of the change in the angular size of the visual stimulus on the observer's retina.
angular velocity threshold
The rate of change in angular size of the visual stimulus that is necessary for an observer to discern that an object's motion has increased or decreased.
annual average daily traffic (AADT)
The total volume passing a point or segment of a highway facility in both directions for one year, divided by the number of days in the year.
apportioned
The formula share from which one receives funds; example: The state's apportionment grew by 5 percent this year.
apportionment
A federal budgetary term that refers to a statutorily prescribed division or assignment of funds; it is based on prescribed formulas in the law and consists of dividing authorized obligation authority for a specific program among transit systems.
approach span
The span or spans connecting the bridge abutment with the main span or spans.
appropriation
A federal budgetary term that refers to an act of Congress that permits federal agencies to incur obligations and make payments out of the treasury for specified purposes; an appropriation act is the most common means of providing budget authority, but in some cases the authorization legislation itself provides the budget authority.
arterial street or highway
A major thoroughfare used primarily for through traffic, rather than access to private land.
articulated bus
An extra-long, high-capacity bus with a rear body section or sections flexibly, but permanently, connected to the forward section; the arrangement allows the vehicle to bend in curves and yet have no interior barrier to movement between the two parts; typically 54 to 60 feet long, an articulated bus has a seating capacity of 60 to 80 passengers.
at-grade
The surface where the rail and a roadway (or pathway) cross at the same level.
attraction signing
Information/supplemental signs featuring logos or verbal messages pointing out places to visit or food, gas and rest area locations.
authorization
Basic, substantive legislation which establishes or continues the legal operation of a federal program or agency, either indefinitely or for a specific period of time, or which sanctions a particular type of obligation or expenditure within a program; an authorization may set appropriation limits.
authorized
Legislation assigns a dollar amount that is the maximum amount that can be spent. They can be trust funds or annual funds. Example: The legislative body authorizes the total amount of funds that can be budgeted for the two-year cycle.
Aviation Trust Fund
Fund established by Congress to pay for improvements to the nation's airports and air traffic control system; money in the fund comes solely from users of the system - primarily a tax on domestic airline tickets.
awarded
This refers to a contract, not funds. A contract is awarded once the selection process has been completed and a contractor has been chosen.