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B/L: Bill of Lading (MARAD2)

BAC: Blood Alcohol Concentration (BTS2) (NHTSA3) (NHTSA4) (NHTSA6)

Back 'Er Down: To stop headway of a tow. (TNDOT1)

Back Chute: An old channel no longer used that may be located behind an island adjacent to the present navigable channel. It is sometimes used during high water stages to navigate without having to buck the strong currents in the main channel. (TNDOT1)

Back Up: To kill headway; to flank or twist tow at foot of crossing or head of bend. (TNDOT1)

Backing Line: A line used on a tow to keep barges from running ahead. (TNDOT1)

Backing Rudders: See Flanking Rudder.

Backwater: 1) Water backed up by a tributary stream; 2) An area of calm water unaffected by the current of a stream. (DOI4) (TNDOT1)

Backwater Curve: The term applied to the profile of the water surface above a dam or other obstruction in a channel. This may also be stated as the effect on the natural water surface profile of either of two confluent streams upstream from their confluence due to flow conditions in the other stream. (TNDOT1)

Backyard Boatbuilder: Person that builds a boat for his own use and not for the purposes of sale. A backyard boatbuilder may subcontract all work. (USCG1)

BAF: Bunker Adjustment Factor (MARAD2)

BAIID: Breath Alcohol Ignition Interlock Device (MM)

Balance of Trade: The difference between a country's total imports and exports; if the exports exceed the imports, a "favorable" balance of trade exists. (TNDOT1)

Balanced Transportation: See Intermodalism (3).

Ballast: Material place on a track bed to hold the track in line and elevation and to distribute its load. Suitable material consists of hard particles (e.g., crushed rock, slag, gravel) that are stable, easily tamped, permeable, and resistant to plant growth. (TRB1)

Balloon: A lighter-than-air aircraft that is not engine driven. (14CFR1)

Balloon Freight: Lightweight freight. (ATA1)

Bar: A submerged or emerged mound, ridge, or succession of ridges of sand or other material extending across the bottom and which may obstruct navigation. (DOI4)

Bareback: Tractor without its semitrailer. (ATA1)

Barge: See also Boat, Tanker.

Barge: A non-selfpropelled vessel. (49CFR171)

Barge: A non-motorized water vessel. usually flat-bottomed and towed or pushed by other craft, used for transporting freight. (TNDOT1)

Barge: Shallow, nonself-propelled vessels used to carry bulk commodities on the rivers and the Great Lakes. (DOE6)

Barge Carriers: Ships designed to carry barges. Some are fitted to act as full container-ships and can carry a varying number of barges and containers at the same time. (MARAD2)

Barrel: (See also Gallon) A unit of volume equal to 42 U.S. gallons at 60 Degrees Fahrenheit. (49CFR194) (49CFR195) (DOE3)

BART: Bay Area Rapid Transit District (FTA4)

Base Period (Off-Peak Period): In transit, the time of day during which vehicle requirements and schedules are not influenced by peak-period passenger volume demands (e.g., between morning and afternoon peak periods). At this time, transit riding is fairly constant and usually low to moderate in volume when compared with peak-period travel. (TRB1)

Basic Grant: The funds available to a State for carrying out an approved State Enforcement Plan (SEP), which include, but are not limited to: 1) Recruiting and training of personnel, payment of salaries and fringe benefits, the acquisition and maintenance of equipment except those at fixed weigh scales for the purposes of weight enforcement, and reasonable overhead costs needed to operate the program; 2) Commencement and conduct of expanded systems of enforcement; 3) Establishment of an effective out-of-service and compliance enforcement system, and 4) Retraining and replacing staff and equipment. (49CFR350)

Basic Utility Stage I Airport: This type of airport serves 75 percent of the single-engine and small twin-engine airplanes used for personal and business purposes. Precision approach operations are not usually anticipated. This airport is designed for small airplanes in Airport Reference Code B-I. (FAA12)

Basic Utility Stage II Airport: This type of airport serves all the airplanes of stage I plus some small business and air taxi-type twin-engine airplanes. Precision approach operations are not usually anticipated.This airport is also designed for small airplanes in Aircraft Reference Code B-I. (FAA12)

Basin: See also Inundation Area.

Basin: Any bowl-shaped depression in the surface of the land or ocean floor. (DOI4)

Bastard Tow: A tow made up of uneven or dissimilar barges. (TNDOT1)

Batture: The land on either side of a river between the low water stage of the river and the top of a levee. (TNDOT1)

Bay/Inlet: A water area that is an opening of the sea/ocean into the land, or of an estuary, lake, or river into its shore. (DOI3)

BCS: Border Cargo Selectivity (USTTA1)

BDL: Bradley International Airport (FAA11)

BEA: Bureau of Economic Analysis, Department of Commerce (BTS2)

Beacon: A fixed signal, mark, or light and associated facilities erected for the guidance of mariners or airplane pilots. (DOI4)

Beam: The width of a ship. (MARAD2)

Bean Hauler: A driver who transports fruits and vegetables. (ATA1)

Bear Trap: A section of movable dam with concrete piers in either side (generally about 100 feet wide) and provided with a gate which may be raised or lowered by compressed air. The bear trap serves as a type of safety valve. When the pool level maintained at the dam becomes too high, the bear trap is lowered to permit the excess water to run out. This pool control feature of movable wicket-type dams is found on the Ohio and Illinois rivers. The Bear trap will always be located on the opposite side of the river from the lock and is very dangerous to approach when open. (TNDOT1)

Bearing: (See also Course, Flight Path) The horizontal direction to or from any point, usually measured clockwise from true north, magnetic north, or some other reference point, through 360 degrees. (FAA8)

Bed-Load Movement: Solids which are transported along the riverbed as a semi suspended sediment. (TNDOT1)

Beginning Milepost: The continuous milepost notation to the nearest 0.01 mile that marks the beginning of any road or trail segment. (DOI2)

Below Minimums: Weather conditions below the minimums prescribed by regulation for the particular action involved; (e.g., landing minimums, takeoff minimums). (FAA4)

Bend: Curve in the river, analogous to a curve in a highway. (TNDOT1)

Berm: The sharp definitive edge of a dredged channel such as in a rock cut. (TNDOT1)

Berth: (See also Wharfage) 1) A specific segment of wharfage where a ship ties up alongside at a pier, quay, wharf, or other structure that provides a breasting surface for the vessel. Typically, this structure is a stationary extension of an improved shore and intended to facilitate the transfer of cargo or passengers. (MARAD1)

Beverage Semitrailer: A van-type, drop-frame semitrailer designed and used specifically for the transport and delivery of bottled or canned beverages which has side-only access for loading and unloading this commodity. (23CFR658)

BFV: Bradley Fighting Vehicle (MTMC1)

BGR: Bangor International Airport (FAA11)

BHM: Birmingham Airport (FAA11)

Bible: The "Golden Rule" safe driving book. (ATA1)

Bicycle: A vehicle having two tandem wheels, propelled solely by human power, upon which any person or persons may ride. (43CFR652)

Bicycle Lane (Bike Lane): A portion of a roadway which has been designated by striping, signing and pavement markings for the preferential or exclusive use of bicyclists. (23CFR652)

Bicycle Path (Bike Path): A bikeway physically separated from motorized vehicular traffic by an open space or barrier and either within the highway right-of-way or within an independent right-of-way. (23CFR652)

Bicycle Route (Bike Route): A segment of a system of bikeways designated by the jurisdiction having authority with appropriate directional and information markers, with or without a specific bicycle route number. (23CFR652)

Bicycles: Includes bicycles of all speeds and sizes that do not have a motor. (FHWA3)

Big Hat: State Trooper. (ATA1)

Big Rigger: Arrogant driver, or one who will drive only long trailers. (ATA1)

Bight of a Bend: Deepest portion of a bend (not in depth of water); sharpest part of a curve. (TNDOT1)

Bikeway: Any road, path, or way which in some manner is specifically designated as being open to bicycle travel, regardless of whether such facilities are designated for the exclusive use of bicycles or are to be shared with other transportation modes. (23CFR652)

Bilateral Trade Agreement: Commerce between two countries based on a reciprocal trade agreement which specifies the quantity of goods to be traded, the time limit of the agreement and that the balances due be remitted directly between the countries. (TNDOT1)

Bill of Lading: A document that establishes the terms of a contract between a shipper and a transportation company. It serves as a document of title, a contract of carriage and a receipt for goods. (MARAD2)

Billing: A transaction conducted by a carrier involving the determination of the proper rate and total charges for a shipment and the issuance of a freight bill. (MARAD1)

Binders: Brakes. (ATA1)

Birdyback: Intermodal transportation system using highway freight containers carried by aircraft. (ATA1)

Blanket Certificate (Authority): Permission granted by the Federal Energy Regulatory Commission (FERC) for a certificate holder to engage in an activity (such as transportation service or sales) on a self implementing or prior notice basis, as appropriate, without case-by-case approval from FERC. (DOE1)

Blind Side: Right side of truck and trailer. (ATA1)

Blind Speed: The rate of departure or closing of a target relative to the radar antenna at which cancellation of the primary radar target by moving target indicator (MTI) circuits in the radar equipment causes a reduction or complete loss of signal. (FAA4)

Blind Spot: An area from which radio transmissions and/or radar echoes cannot be received. The term is also used to describe portions of the airport not visible from the control tower. (FAA4)

Blind Velocity: The radial velocity of a moving target such that the target is not seen on primary radars fitted with certain forms of fixed echo suppression. (FAA4)

Blind Zone: See Blind Spot.

BLM: Bureau of Land Management (OFR1)

Block: A length of track of defined limits, the use of which by trains is governed by block signals, cab signals, or both. (49CFR236)

Block Signal: A roadway signal operated either automatically or manually at the entrance to a block. (49CFR236)

Block Signal System: A method of governing the movement of trains into or within one or more blocks by block signals or cab signals. (49CFR236)

Block to Block Time: See Flight Time.

Blocked: Phraseology used to indicate that a radio transmission has been distorted or interrupted due to multiple simultaneous radio transmissions. (FAA4)

Blood Alcohol Concentration (BAC): Is measured as a percentage by weight of alcohol in the blood (grams/deciliter). A positive BAC level (0.01 g/dl and higher) indicates that alcohol was consumed by the person tested. A BAC level of 0.10 g/dl or more indicates that the person was intoxicated. (NHTSA3)

Blow Him Down: To sound the danger signal in case of misunderstood passing signals, when the pilot on the other boat refuses to obey signals, or when just desiring to pass information. (TNDOT1)

BLS: Bureau of Labor Statistics (BTS2)

BLT: Bacon, Lettuce and Tomato Sandwich

Blue Signal: A clearly distinguishable blue flag or blue light by day and a blue light at night. When attached to the operating controls of a locomotive, it need not be lighted if the inside of the cab area of the locomotive is sufficiently lighted so as to make the blue signal clearly distinguishable. (49CFR218)

Bluff Bar: A sandbar having a sharp drop-off into deep water. Also called a "bluff reef." (TNDOT1)

BN: Burlington Northern (BTS2)

BNA: Nashville International Airport (FAA11)

BNIP: Bridge Needs and Investment Process (FHWA12)

Board of Commissioners: A legal body of 3 to 9 individuals having broad administrative authority over a river port's operation. This board is primarily concerned with the development and determination of policies of the port authority. (TNDOT1)

Boat: See also Barge, General Cargo Ship, Motorboat, Towboat, Tugboat, Vessel.

Boat Trailer: A trailer designed with cradle-type mountings to transport a boat and configured to permit launching of the boat from the rear of the trailer. (49CFR571)

Boat Transporters: Any vehicle combination designed and used specifically to transport assembled boats and boat hulls. Boats may be partially disassembled to facilitate transporting. (23CFR658)

BOAT/US: Boat Owners Association of the United States (USCG1)

Boating Safety Circular (BSC): Published by COMDT (G-NAB) for free distribution to boat and equipment manufacturers, dealers, marinas, yacht clubs, OCMI personnel and other boating organizations. Information in the BSC concerns boating standards and boating safety in general. (USCG1)

BOC: Back of Cab (TII2) (TII1)

Bodily Injury: Injury to the body, sickness, or disease including death resulting from any of these. (49CFR387)

Body: See also Chassis.

Body: Semitrailer. (ATA1)

Body Type: Refers to the individual classifications of motor vehicles by their design structure based on definitions developed by the Society of Automotive Engineers. (NHTSA2)


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