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B



barge
Flat-bottomed boat designed to carry cargo on inland waterways, usually without engines or crew accommodations; barges can be lashed together and either pushed or pulled by tugs, carrying cargo of 60,000 tons or more; small barges for carrying cargo between ship and shore are known as lighters.
Barnes' Dance timing
Type of exclusive signal timing phase where pedestrians may also cross diagonally, in addition to crossing either street; also referred to as scramble timing.
base fare
The price charged to one adult for one transit ride; excludes transfer charges, zone charges, express service charges, peak period surcharges and reduced fares.
beam
A linear structural member designed to span from one support to another.
benefit/cost (B/C) ratio
B/C is used to compare the benefit versus the cost of proposed alternatives. For highway projects, benefits may include reduced fuel consumption, travel time and air pollution; costs may include construction, right of way and maintenance.
bent
A substructure unit supporting each end of a bridge span; also called a pier; made up of two or more columns or column-like members connected at their top most ends by a cap, strut or other member holding them in their correct positions.
bicycle facilities
A general term denoting improvements and provisions made to accommodate or encourage bicycling, including parking facilities, all bikeways and shared roadways not specifically designated for bicycle use.
bid and bid process
The process of a public agency requesting proposals for a specific project or scope of work and the response from an individual or firm to secure a contract.
bike lane
A portion of a roadway that has been designated by striping, signing and pavement markings for the preferential or exclusive use of bicyclists.
bikeway
A bikeway is created when a road has the appropriate design treatment for bicyclists, based on motor vehicle traffic volumes and speeds. On-road bikeways include a shared roadway, shoulder bikeway, bike lane or bicycle boulevard design treatments.
borrow
Site for obtaining earth materials for roadway embankment construction.
bottleneck
Highway sections that experience operational problems, such as congestion; bottlenecks may result from factors other than reduced roadway width; for example, the close spacing of exit and entrance ramps can cause weaving patterns that result in congestion; a less obvious example is a steep freeway grade that can slow trucks and cause a localized "bottleneck."
bow
The front of a vessel.
box girder
A support beam that is a hollow box; its cross section is a rectangle or square.
boxcar
An enclosed car used for general service and especially for lading that must be protected from weather.
brake reaction time
The interval between the instant that the driver recognizes the presence of an object or hazard on the roadway ahead and the driver actually applies the brakes.
branch railroad
Nonclass 1 railroad.
branchline
A secondary line of a railroad, not the main line.
budget authority
A federal budgetary term that refers to legal authority given by Congress to federal agencies to make funds available for obligation or expenditure.
budget resolution
A federal budgetary term that refers to a concurrent resolution passed by Congress, but not requiring the signature of the president, setting forth the congressional budget for each of five fiscal years; the budget resolution sets forth various budget total and functional allocations, and may include reconciliation instructions to designated House or Senate committees.
bulk
Cargo shipped in loose condition and of a homogeneous nature; cargoes that are shipped unpackaged either dry, such as grain and ore, or liquid, such as petroleum products; bulk service generally is not provided on a regularly scheduled basis, but rather as needed, on specialized ships, transporting a specific commodity.
bulk transfer
The transfer of bulk products, such as plastic pellets or liquid sweeteners, from one mode of transportation to another; bulk transfer permits off-rail shippers and receivers of varied commodities to combine rail's long-haul efficiencies with truck's convenient door-to-door delivery.
bus
A rubber-tired vehicle designed for roadway operation to transport a large number of people for public transportation service.
bus, charter
A bus transporting a group of persons who, pursuant to a common purpose, and under a single contract at a fixed price, have acquired the exclusive use of a bus to travel together under an itinerary.
bus, intercity
A bus with front doors only, high-backed seats, separate luggage compartments, and usually with restroom facilities for use in high-speed, long-distance service.
buttonhook ramp
J-shaped ramp that connects to a parallel or diagonal street or frontage road, which is often well removed from the interchange structure and other ramps.