BTS | Dictionary

Tag: The official U.S. Government motor vehicle license plate, District of Columbia license plate, or license plate of any State, Territory, or possession of the United States. (GSA2)

TAG: Transportation Alternatives Group (Transportation 2020) (MTMC1)

TAG: Transportation Acronym Guide (BTS7)

TAG: Tactical Air Group (MTMC1)

Tag Axle: A nonpowered vehicle axle that helps distribute the load. (TRB1)

Tail Lamps: Lamps used to designate the rear of a motor vehicle. (49CFR393)

Tailboard Artist: One who thinks he is a perfect driver. (ATA1)

Tailgate: The outlet of a natural gas processing plant where dry residue gas is delivered or redelivered for sale or transportation. (DOE5)

Tailgate (Lower Lock Gate): A gate located at the downstream of a lock in the tailwater of a dam. (TNDOT1)

Tailgating: Driving too closely behind the vehicle ahead. (ATA1)

Tailwater: A term to indicate the depth of water above pool stage immediately below a dam when that dam is passing water in a non-sufficient amount to raise the stage of the water immediately below the dam. A term used primarily in the Upper Mississippi River area. (TNDOT1)

Tainter Gate: A large gate used to control the flow of water through or over a dam; such gates have a cylindrical surface with the convex side facing upstream. (TNDOT1)

Takeoff Distance Available (TODA): The runway length available for takeoff plus the length of any remaining runway and/or clearway beyond the far end. (FAA12)

Takeoff Power: 1) With respect to reciprocating engines, means the brake horsepower that is developed under standard sea level conditions, and under the maximum conditions of crankshaft rotational speed and engine manifold pressure approved for the normal takeoff, and limited in continuous use to the period of time shown in the approved engine specification; and 2) With respect to turbine engines, means the brake horsepower that is developed under static conditions at a specified altitude and atmospheric temperature, and under the maximum conditions of rotor shaft rotational speed and gas temperature approved for the normal takeoff, and limited in continuous use to the period of time shown in the approved engine specification. (14CFR1)

Takeoff Run Available (TORA): The runway length declared available and suitable for the ground run of an airplane taking off. (FAA12)

Takeoff Safety: A referenced airspeed obtained after lift-off at which the required one-engine-inoperative climb performance can be achieved. (14CFR1)

Takeoff Thrust: With respect to turbine engines, means the jet thrust that is developed under static conditions at a specific altitude and atmospheric temperature under the maximum conditions of rotorshaft rotational speed and gas temperature approved for the normal takeoff, and limited in continuous use to the period of time shown in the approved engine specification. (14CFR1)

Talus: Slopes of broken rock debris on a mountainside. (DOI4)

TANB: Trailerable Aids To Navigation Boat (USCG5)

Tandem: (See also Dual Drive Tandem) Semitrailer or tractor with two rear axles. (ATA1)

Tandem Axle: Two axles operated from a single suspension. (TII1) (TII2)

Tandem Axle Weight: The total weight transmitted to the road by two or more consecutive axles whose centers may be included between parallel transverse vertical planes space more than 40 inches and not more than 96 inches apart, extending across the full width of the vehicle. The Federal tandem axle weight limit on the Interstate System is 34,000 pounds. (23CFR658)

Tandem Wing: A configuration having two wings of similar span, mounted in tandem. (14CFR1)

Tank: A structure used for the storage of fluids. (DOI4)

Tank Barge: A large, flat-bottomed, non-selfpropelled, compartmented, decked-over barge used for all types of liquid cargo (petroleum, molasses, chemicals, etc). (TNDOT1)

Tank Car: A railroad car consisting of a large cylindrical container attached to the railcar truck and used to transport liquids in bulk. (FRA3)

Tank Farm: An installation used by gathering and trunk pipeline companies, crude oil producers, and terminal operators (except refineries) to store crude oil. (DOE5)

Tank Vehicle: Any commercial motor vehicle that is designed to transport any liquid or gaseous materials within a tank that is either permanently or temporarily attached to the vehicle or the chassis. Such vehicles include, but are not limited to, cargo tanks and portable tanks, as defined in 49 CFR 171. However, this definition does not include portable tanks having a rated capacity under 1,000 gallons. (49CFR383)

Tanker: See also Barge.

Tanker: Truck, semitrailer, or trailer with a tank body for hauling liquids. (ATA1)

Tanker: An oceangoing ship specially designed to haul liquid bulk cargo in world trade. (TNDOT1)

Tanker and Barge: Vessels that transport crude oil or petroleum products. Data are reported for movements between Petroleum and Administration for Defense (PAD) Districts; from a PAD District to the Panama Canal; or from the Panama Canal to a PAD District. (DOE5)

Tanker Man: Person trained, qualified, and certified to supervise transfer of liquid cargo (fuels) from shore to the barge. (TNDOT1)

Tare Weight: The curb weight plus the weight of the mounted body. Tare weight is also known as actual weight. (BOC3) (GSA2)

Tare Weight: The weight of a container and/or packing materials without the weight of the goods it contains. (MARAD2)

TARGET: Transportability Analysis Reports Generator (MTMC1)

Tariff: A published volume of rate schedules and general terms and conditions under which a product or service will be supplied. (DOE5)

Tariff: The charges, rates, and rules of transportation companies usually set forth in an industry publication. (MARAD1)

Tarp: Tarpaulin cover for open top trailers. (ATA1)

TARP: Transportation Accounts Receivable and Payment System (GSA2)

TASS: Terminal Air Surveillance System (FAA7)

TATCA: Terminal Air Traffic Control Automation (FAA17) (FAA7) (FAA19)

Tattle Tale: (See also Squealer) Tachograph. (ATA1)

TAVT: Terminal Airspace Visualization Tool (FAA17)

Taxi: See also Motor Vehicle.

Taxi: The use of a taxicab by a driver for hire or by a passenger for fare. Also includes airport limousines. Does not include rental cars if they are privately operated and not picking up passengers in return for fare. (FHWA3)

Taxicabs: Establishments primarily engaged in furnishing passenger transportation by automobiles not operated on regular schedule or between fixed terminals. Taxicab fleet owners and organizations are included, regardless of whether drivers are hired or rent their cabs or are otherwise compensated. (BOC1)

Taxilane (TL): The portion of the aircraft parking area used for access between taxiways and aircraft parking positions. (FAA12)

Taximeter: A mechanical or electrical device in a taxicab that records and indicates a charge or fare calculated according to distance traveled, waiting time, initial charge, number of passengers, and other charges authorized by ordinance or by rule. Some taximeters are part of electronic dispatching systems. (TRB1)

Taxiway (TW): A defined path established for the taxing of aircraft from one part of an airport to another. (FAA12)

Taxiway Safety Area (TSA): The surface alongside the taxiway prepared or suitable for reducing the risk of damage to an airplane unintentionally departing the taxiway. (FAA12)

TAZ: Traffic Analysis Zone (FHWA13)

TAZ: Transportation Analysis Zone (MM)

TBS: Talk Between Ships (MTMC1)

TCA: Terminal Control Area (FAA17) (FAA8)

TCA: Traffic Control Airport Or Tower Control Airport (FAA6)

TCACCIS: Transportation Coordinator Automated Command and Control Information System (MTMC1)

TCADS: Truck Crash Analysis Data System (FHWA10)

TCAS: Traffic Alert and Collision Avoidance System (14CFR1) (FAA17) (FAA6) (FAA7)

TCC: Tank Car Committee (RSPA1)

TCC: Transportation Component Command (MTMC1)

TCC: Transportation Control Center (FTA4)

TCCC: Tower Control Computer Complex (FAA17) (FAA7) (FAA19)

TCD: Traffic Control Devices (MOCD)

TCH: Threshold Crossing Height (FAA4)

TCIC: Technical Committee On Industrial Classification (BTS8)

TCLT: Tentative Calculated Landing Time (FAA4)

TCM: Transportation Control Measure (MOCD)

TCMD: Transportation Control and Movement Document (MTMC1)

TCN: Transportation Control Number (MTMC1)

TCON: Trailer Container (MTMC1)

TCON: Transportation Constructor (MTMC1)

TCP: Traffic Control Point (MTMC1)

TCP: Transportation Control Plan (MTMC1)

TCP/IP: Transmission Control Protocol/Internet Protocol (BTS9)

TCRP: Transit Cooperative Research Program (FTA4)

TCT: Total Cost Transportation (MTMC1)

TCU: Transportation Control Unit (MTMC1)

TD: Touchdown

TD: Transportation Disadvantaged (MOCD)

TDC: U.S. Travel Data Center (BTS8)

TDDS: Talking Directory Display System (FTA4)

TDLS: Tower Data - Link Services (FAA19)

TDM: Transportation Demand Management (MOCD)

TDP: Transit Development Program (TRB1)

TDR: Transportation Discrepancy Report (MTMC1)

TDS: Transportation Data Sampler (BTS8)

TDWR: Terminal Doppler Weather Radar (FAA19) (FAA8)

TDZE: Touchdown Zone Elevation (FAA4)

TEAM: Techniques for Effective Alcohol Management (NHTSA6)

Technical Factory Visit: A visit of officer in charge marine inspection (OCMI) personnel to a manufacturing facility to check for compliance with standards and regulations, examine products and answer technical questions. (USCG1)

Technology Transfer: Those activities that lead to the adoption of a new technique or product by users and involves dissemination, demonstration, training, and other activities that lead to eventual innovation. (23CFR420)

Temporary Living Quarters: A space in the interior of an automobile in which people may temporarily live and which includes sleeping surfaces, such as beds, and household conveniences, such as a sink, stove, refrigerator, or toilet. (49CFR523)

Terawatt Hour (TWH): One trillion watt hours. (DOE5)

Terminal: Any location where freight either originates, terminates, or is handled in the transportation process; or commercial motor carriers maintain operating facilities. (23CFR658)

Terminal: Any facility on the inland system designed for on-loading or off-loading of barges. (TNDOT1)

Terminal and Joint Terminal Maintenance For Motor Freight Transport Facility: Establishments primarily engaged in the operation of terminal facilities used by highway-type property carrying vehicles. Also included are terminals which provide maintenance and service for motor vehicles. (BOC1)

Terminal and Service For Motor Vehicle Passenger Transportation Facility: Establishments primarily engaged in the operation of motor vehicle passenger terminals and of maintenance and service facilities, not operated by companies that also furnish motor vehicle passenger transportation. (BOC1)

Terminal Area: A general term used to describe airspace in which approach control service or airport traffic control service is provided. (FAA2) (FAA8)

Terminal Area Facility: A facility providing air traffic control service for arriving and departing Instrument Flight Rule (IFR), Visual Flight Rule (VFR), Special Visual Flight Rules (VFR), Special Instrument Flight Rules (IFR) aircraft and, on occasion, en route aircraft. (FAA8)

Terminal Facility Activity: The sum of Total Airport Operations + Total Instrument Operations which equals Local Operations + Itinerant Operations + Primary Instrument Operations + Secondary Instrument Operations + Instrument Overflights. (FAA3)

Terminal Radar Approach Control (TRACON): A Federal Aviation Administration (FAA) air traffic control facility using radar and air/ground communications to provide approach control services to aircraft arriving, departing, or transiting the airspace controlled by the facility. Service may be provided to both civil and military airports. (FAA10) (FAA13) (FAA14)

Terminal Storage: Service of providing warehouse or other terminal facilities for the storage of inbound or outbound cargo after the expiration of free time, including wharf storage, shipside storage, closed or covered storage, open or ground storage, bonded storage and refrigerated storage, after storage arrangements have been made. (MARAD1)

Terminated Carload: A carload which ends its journey and is unloaded on a particular railroad. (AAR1)

TERPS: Terminal Instrument Procedures (FAA17) (FAA7) (FAA19)

Terrace: A steplike feature between higher and lower ground; a relatively flat or gently inclined shelf of earth, backed and fronted by steep slopes or manmade retaining walls. (DOI4)

Territorial Highway System (THS): The full name is Federal-aid Territorial Highway System. A system of arterial and collector highways, plus inter-island connectors that are established under 23 U.S.C. 215 by each territory (Guam, Northern Marianas Islands, Samoa, and the Virgin Islands). (FHWA2)

Test Procedures: Specifies the methods and equipment the Coast Guard uses in determining whether boats comply with applicable standards. (USCG1)

TEU: Twenty-Foot Container Equivalent Unit (MARAD3)

Texas: That part of the upper deck of a river steamboat abaft the stacks used for officers' quarters. (TNDOT1)

TFHRC: Turner - Fairbank Highway Research Center (FHWA8)

TFM: Traffic Flow Management (FAA17)

TFP: Total Factor Productivity (BTS2)

TFVC: Traffic Flow Visualization and Control (FHWA14)

TGA: Trans Global Airlines (FAA7)

TGIF: Thank God Its Friday

TH: Threshold (FAA12)

Thalweg: The deepest water at any point in the river. The longitudinal line of greatest continuous depth in the river channel. (TNDOT1)

Thanksgiving Rise: An annual event on the Ohio River when the river swells to a crest around Thanksgiving time. (TNDOT1)

Then On Down: Channel report term written as proceeding to a designated mile or designated bank, then on down to the end of another designated location, such as "fourth dike below this light." (TNDOT1)

Thermal Limit: The maximum amount of power a transmission line can carry without suffering heat-related deterioration of line equipment, particularly conductors. (DOE5)

Thermal Storage: Storing heat for use at a later time. For example, ceramic bricks can be charged up to 1,200 degrees Fahrenheit in an 8-hour period and the heat released over the next 16 hours. (DOE5)

Thermosiphon System: A solar collector system for water heating in which circulation of the collection fluid through the storage loop is provided solely by the temperature and density difference between the hot and cold fluids. (DOE5)

Third Party: (See also Accident) When referring to motor vehicle accidents; the Government being the first party and the government owned vehicle (GOV) operator being the second party, the third party is the other concern in an accident. (GSA2)

Third Rail: An electric conductor, located alongside the running rail, from which power is collected by means of a sliding shoe attached to the truck of electric rail cars or locomotives. (TRB1)

Third Structure Tax: Any tax on road users other than registration fees or fuel taxes. (ATA2)

Threshold (TH): The beginning of that portion of the runway available for landing. When the threshold is located at a point other than at the beginning of the pavement, it is referred to as either a displaced or relocated threshold. (FAA12)

Through Bill of Lading: Bill of lading covering transportation through more than one mode in the chain of transport from shipper to consignee. (MARAD1)

Throughput: Actual or estimated volume of natural gas that may be carried on a pipeline over a period of time. (DOE1)

Throughput: A measure of productivity for cargo (i.e. containers per day/month/year) processed and handled through a port facility. (MARAD1)

Throughput Capacity: The estimated potential tonnage of cargo that can be processed and handled through a port terminal or berthing facility during a given time period, determined by the design specifications of the terminal. (MARAD1)

Throughput Charge: The charge for moving a container through a container yard off or onto a ship. (MARAD2)

THS: Territorial Highway System (FHWA8)

TIA: Transportation In America (BTS8)

TIC: Traveler Information Center (FTA4)

Ticketing and Fare Collection: All activities associated with fare collection and counting activities including supervision and clerical support. Includes printing, distributing, selling and controlling of tickets, tokens and passes; pulling and transporting vaults to counting facilities; counting and auditing of fare collection; and, providing security for the fare collection process. (FTA1)

Tidal: Flat foreshore area that is submerged at high tide, exposed or a wash at low tide, and generally devoid of vegetation. (DOI3)

Tidal Gauge: An instrument for measuring the height of the tide. (DOI4)

Tidegate: (See also Gate, Floodgate) Gate with a free-swinging barrier that is placed near or at the outlet of a conduit flowing into a body of water subject to high water from tides in order to separate fresh from salt water. (DOI3)

TIDS: Tower Integrated Display System (FAA17)

Tie Line: A transmission line connecting two or more power systems. (DOE5)

Tie Off to Bank: To moor one or more barges to the bank of the river, utilizing trees or any other structure available for securing the mooring wires. (TNDOT1)

Tied Up: When roadway is obstructed. (ATA1)

TIFA: Trucks Involved In Fatal Accidents (NHTSA4)

TIGER: Topological Integrated Geographic Encoding & Referencing (FHWA13)

Till: Channel report term meaning to steer toward a certain mark in a direct line until the occurrence or existence of another named fact taken place. (TNDOT1)

Till From: An old river phrase meaning that after steering past a set of marks, the mark that is on the stern now becomes "till." One should keep the past mark on the stern and lineup. (TNDOT1)

Tilt Cab: Vehicle designed with engine beneath cab and having provision for tilting the cab forward on a pivot near the front bumper to provide easy access to the engine. (TII1) (TII2)

Timberhead: One or two upright pins or steel bollards on the heads and stems of barges whereby the barges are coupled together for towing end to end. The term originated from the wooden timbers mounted on early wooden barges that were prevalent for transporting coal many years ago. (TNDOT1)

Time In Service: With respect to maintenance time records, means the time from the moment an aircraft leaves the surface of the earth until it touches it at the next point of landing. (14CFR1)

Time Locking: A method of locking, either mechanical or electrical, which, after a signal has been caused to display an aspect to proceed, prevents, until after the expiration of a predetermined time interval after such signal has been caused to display its most restrictive aspect, the operation of any interlocked or electrically locked switch, movable-point frog, or derail in the route governed by that signal, and which prevents an aspect to proceed from being displayed for any conflicting route. (49CFR236)

Time On Sortie: Total time on sortie from homeport/station or diversion from another mission until return to homeport/station or return for replenishment. (USCG3)

Time Release: A device used to prevent the operation of an operative unit until after the expiration of a predetermined time interval after the device has been actuated. (49CFR236)

Time Service Begins: Start of morning transit service, i.e., the time when a revenue service vehicle leaves the garage or point of dispatch. (FTA1)

Time Service Ends: End of night transit service, i.e., the time when a revenue service vehicle returns to the garage or point of dispatch. (FTA1)

Time Zone: A geographic region within which the same standard time is used. (DOI4)

Timed Transfer System: A transit network consisting of one or more nodes (transit centers) and routes or lines radiating from them. The system is designed so that transit vehicles on all or most of the routes or lines are scheduled to arrive at a transit center simultaneously and depart a few minutes later; thus transfers among all the routes and lines involve virtually no waiting. TTS is typically used in suburban areas and for night service; in other words, for those cases in which headways are long. (TRB1)

Timing Relay: A relay which will not close its front contacts or open its back contacts, or both, until the expiration of a definite time interval after the relay has been energized. (49CFR236)

TIP: Transportation Improvement Program (TRB1)

Tip Fin: See Winglet.

Tipple: A central facility used in loading coal for transportation by rail or truck. (DOE5)

Tire Capacity: The rated capacity in pounds that the tire is designed to support, as established by the current Tire and Rim Association ratings. (GSA2)

TIRES: Transportation Interface and Reporting System (GSA2)

TIUS: Truck Inventory and Use Survey (BTS2)

TL: Taxilane (FAA12)

TL: Truckload (BTS2) (MARAD1)

TLC: Tender Loving Care

TLOF: Touchdown Lift-Off Surface (OST3)

TM: Traffic Manager (MTMC1)

TMA: Traffic Management Advisor (FAA17) (FAA7)

TMA: Traffic Management Agency (MTMC1)

TMA: Transportation Management Association (FTA4)

TMC: Traffic Message Channel (FHWA15)

TMCC: Traffic Management Computer Complex (FAA17)

TMG: Traffic Monitoring Guide (FHWA8)

TMIL: Traffic Management Information Letter (MTMC1)

TMIP: Travel Model Improvement Program (BTS2)

TML: Television Microwave Link (FAA19)

TML: Traffic Management Laboratory (FHWA14)

TMP: Transportation Motor Pool (MTMC1)

TMPA: Traffic Management Program Alert (FAA4)

TMS: Traffic Management System (FAA17) (FAA19)

TMS: Traffic Monitoring System (FHWA8)

TMU: Traffic Management Unit (FAA17) (FAA19) (FAA8)

TNA: Thermal Neutron Analysis (FAA1)

TNRDA: Transit Network Route Decision Aid (FHWA15)

TO: Transportation Officer (MTMC1)

To Halfway Between: Channel report term meaning to steer halfway between two separately designated reference objects. (TNDOT1)

TOC: Transportation Operating Command (MTMC1)

TODA: Takeoff Distance Available (FAA12)

TOFC: Trailer On Flat Car (AAR1) (ATA2) (BTS2)

Toll Road: Travel fee is collected at entry or exit. (DOI3)

Ton Mile: (See also Average Length of Haul) One ton moved one mile. (AIA1)

Ton Mile: One ton (2,000 pounds) transported one statue mile (5,280). Ton-miles are computed by multiplying the aircraft miles flown on each inter-airport hop by the number of tons carried on that hop. (BTS5) (BTS6)

Ton Mile: A unit of measure equal to the movement of one ton of railroad lading for a distance of one mile. (DOE6) (FRA3)

Ton Miles Tax: A tax calculated by measuring the weight of each truck for each trip. The gross weight is assigned a tax rate which is multiplied by the miles of travel. (ATA2)

Ton Offered Kilometer: Unit of measure representing the movement of one ton available in a freight vessel when performing the services for which it is primarily intended over one kilometer. (TNDOT1)

Ton-Deadweight: The carrying capacity of the ship in terms of the weight in tons of the cargo, fuel, provisions, and passengers which a vessel can carry. (TNDOT1)

Ton-Displacement: The weight of the volume of water which the fully loaded ship displaces. (TNDOT1)

Ton-Kilometer By Inland Waterways: Unit of measure of goods transport which represents the transport of one ton by inland waterways over one kilometer. (TNDOT1)

Ton-Registered: The cubical contents or burden of a vessel in tons of 100 cubic feet. The space within a vessel in units of 100 cubic feet. (TNDOT1)

Tonne: See Metric Ton.

Tooling Down the Highway: Driving vehicle along at normal speed. (ATA1)

Toothpick: Steel bar about 3 feet long placed in ratchet ends to keep wire from turning when tightening ratchet. (TNDOT1)

Top Around: The turning of a tow from upbound to downbound, either intentionally or unintentionally. (TNDOT1)

Top Plate: A metal plate secured to a locking bracket to prevent the cross locking from being forced out of the bracket. (49CFR236)

Top Shell: The tank car tank surface, excluding the head ends and bottom shell of the tank car tank. (49CFR171)

TORA: Take - Off Run Available (FAA12)

Torque: The amount of twisting effort exerted at the crankshaft by an engine. The unit of measure is a pound-foot which represents a force of one pound acting at right angles at the end of an arm one foot long. 1) gross torque: the maximum torque developed by an engine without allowing for the power absorbed by accessory units; 2) net torque: the torque available at the flywheel after the power required by engine accessories has been provided. (TII1) (TII2)

Torso Line: The line connecting the "H" point and the shoulder reference point as defined in Society of Automotive Engineers (SAE) Recommended Practice J787g, "Motor Vehicle Seat Belt Anchorage," September 1966. (49CFR571)

Total Aircraft Revenue Mile: The distance flown by aircraft in revenue passenger and/or nonpassenger service, including extra sections. (BTS5)

Total Departures Performed In All Services: The total number of aircraft takeoffs made in scheduled and nonscheduled service. (FAA15)

Total Departures Performed In Nonscheduled Services: The total number of aircraft takeoffs made in nonscheduled service. (FAA15)

Total Departures Performed In Scheduled Service: The total number of aircraft takeoffs made in scheduled service including extra sections. (FAA15)

Total Energy: All energy consumed by end-users, including electricity but excluding the energy consumed at electric utilities to generate electricity. (In estimating energy expenditures, there are no fuel-associated expenditures for hydroelectric power, geothermal energy, solar power, or wind energy, and the quantifiable expenditures for process fuel and intermediate products are excluded.) (DOE5)

Total Energy Consumption: The sum of fossil fuel consumption by the five sectors (residential, commercial, industrial, transportation, and electric utility) plus hydroelectric power, nuclear electric power, net imports of coal coke, and electricity generated for distribution from wood, waste, geothermal, wind, photovoltaic, and solar thermal energy. (DOE3) (DOE5)

Total Facility Activity: The sum of En Route Facility Activity + Terminal Facility Activity. (FAA3)

Total Flight Service: The sum of flight plans originated and pilot briefs multiplied by two, plus the number of aircraft contacted. No credit is allowed for airport advisories or radio contacts. (FAA13)

Total Miles on Active Vehicle During the Period: The total miles acumulated on all active vehicles in the group during the period. (FTA1)

Total Operations: All arrivals and departures performed by military, general aviation, commuter/air taxi, and air carrier aircraft. (FAA14)

Total Revenue Load Factor: The percent that revenue ton-miles (passenger and nonpassenger) are of available ton-miles in revenue services, representing the proportion of the overall capacity that is actually sold and utilized. (BTS5)

Total Ton-Miles: The aircraft miles flown on each inter-airport hop multiplied by the tons of revenue traffic (passenger and nonpassenger) carrier on that hop. (BTS6)

Tour Operators: Establishments primarily engaged in arranging and assembling tours for sale through travel agents. Tour operators primarily engaged in selling their own tours directly to travelers are also included in this industry. (BOC1)

Tow: One or more barges or other floating vessels in the charge of a self-propelled vessel which has undertaken to transport such responsibility elsewhere. A tow is made-up when it has been hitched together and made ready for moving. A barge moored to the front of a towing vessel is the towbarge and the ones out in front are the lead barges. When a barge is towed alongside a towboat, it is "slung under her arm" or on the hip". When pulled behind, the barges are said to be "railroaded." When loosely coupled behind, it is called the "mule train." (TNDOT1)

Tow Line: A holding up line; normally a lashing from the forward head of one barge to the after head of a barge alongside. (TNDOT1)

Towboat: (See also Boat, Motorboat, Tug) A self-propelled, compact, shallow-draft boat with a squared bow and towing "knees" for pushing tows of barges on inland waterways. In early river transportation, the freight-carrying vessels were pulled or "towed." The contemporary method is to push barges but the traditional term "towboat" is still used for the modern barge pushers instead of the more accurate term "pushboat". (TNDOT1)

Tower: A tall framework or structure, the elevation of which is functional. (DOI4)

Towhead: A small island or spit of land extending above or below the main or larger island. It may or may not be recently formed. (TNDOT1)

Towing: Engaged in towing any vessel or object, other than a person. (USCG2)

Towing and Tugboat Service: Establishments primarily engaged in furnishing marine towing and tugboat services in the performance of auxiliary or terminal services in harbor areas. The vessels used in performing these services do not carry cargo or passengers. (BOC1)

Towing Knees: The heavily constructed steel angles mounted in a fixed position on the bow of all western river towboats to enable them to push against the stern of barges. (TNDOT1)

TP: Telecommunications Processor (FAA7)

TP: Tire Pressure (MTMC1)

TP: Trailer Point (MTMC1)

TP: Total Particulate Matter (BTS8)

TPA: Tampa International Airport (FAA11)

TPER: Total Primary Energy Requirement (BTS2)

TPS: Transportation Protective Service (MTMC1)

TPSIS: Transportation Planning Support Information System (TRB1)

TQM: Total Quality Management

TR: Transportation Request (FHWA13)

Track: A pair of rails over which railway vehicles can run. (UN1)

Track Circuit: An electrical circuit of which the rails of the track form a part. (49CFR236)

Track Damage: All costs, including labor and material, associated with the repair or replacement in kind of signals, track, track structures (including bridges or tunnels) or roadbeds that were damaged in a collision, derailment or other reportable event. When track, signals, structures, etc. are damaged beyond repair, the current cost of new materials is to be used. However, replacement of second-hand rail with second-hand rail, may be charged at the current cost of such rail. (FRA2)

Track Mile: (See also Miles of Track Operated) One mile of single track. (AAR1)

Trackage Rights Agreement: An agreement through which a railroad obtains access and provides service over tracks owned by another railroad where the owning railroad retains the responsibility for operating and maintaining the tracks. (49CFR245)

Tracked Air Cushion Vehicle: A laterally guided vehicle that is suspended above the track by an air cushion system. (TRB1)

Tracked Levitated Vehicle: A laterally guided vehicle that is suspended above the track by magnetic levitation. (TRB1)

Trackless Trolley: Another name for "trolleybus." (APTA1)

TRACON: Terminal Radar Approach Control (FAA17) (FAA7) (FAA19) (FAA8) (FAA14)

Tractor: A vehicle designed for pulling loads greater than the weight actually applied to the vehicle. The trailer on which the load is carried is connected to the tractor via the fifth wheel. (TII1) (TII2)

Tractor (or Truck Tractor): The noncargo carrying power unit that operates in combination with a semitrailer or trailer, except that a truck tractor and semitrailer engaged in the transportation of automobiles may transport motor vehicles on part of the power unit. (23CFR658)

Tractor-Semitrailer: A combination vehicle consisting of a power unit (tractor) and a semitrailer. (ATA2)

Traffic Accident: An accident that involved a motor vehicle that occurred on a public highway or road in the United States and that resulted in property damage or personal injury. Does not include accidents that happened in a parking lot, in a driveway, on a private road, or in a foreign country. (FHWA3)

Traffic Alert and Collision Avoidance, Type I System (TCAS): Utilizes interrogations of, and replies from, airborne radar beacon transponders and provides traffic advisories to the pilot. (14CFR1)

Traffic Alert and Collision Avoidance, Type II System (TCAS): Utilizes interrogations of, and replies from airborne radar beacon transponders and provides traffic advisories and resolution advisories in the vertical plane. (14CFR1)

Traffic Alert and Collision Avoidance, Type III System (TCAS): Utilizes interrogation of, and replies from, airborne radar beacon transponders and provides traffic advisories and resolution advisories in the vertical and horizontal planes to the pilot. (14CFR1)

Traffic Assignment Zone: In planning, a division of a study area that is represented by a centroid and used for traffic assignment purposes. (TRB1)

Traffic Circle: A junction of roads that form a circle around which traffic normally moves in one direction. (DOI3)

Traffic Control Device: A sign, signal, marking, or other device placed on or adjacent to a street or highway, by authority of a public body or official that has jurisdiction, to regulate, warn, or guide traffic. (TRB1)

Traffic Control System: A block signal system under which train movements are authorized by block signals whose indications supersede the superiority of trains for both opposing and following movements on the same track. (49CFR236)

Traffic Count: A record of the number of vehicles, people aboard vehicles, or both, that pass a given checkpoint during a given time period. (TRB1)

Traffic Flow Management: The process that ensures optimum flow of air traffic to and through areas during times when demand exceeds, or is expected to exceed, the available capacity of the system; an element of the air traffic management process. (FAA7)

Traffic Inspection Facility: An area having facilities to examine pedestrian and vehicular traffic and/or cargo. (DOI3)

Traffic Known: With respect to Air Traffic Control (ATC) clearances, means aircraft whose altitude, position, and intentions are known to ATC. (FAA4)

Traffic Locking: Electric locking which prevents the manipulation of levers or other devices for changing the direction of traffic on a section of track while that section is occupied or while a signal displays an aspect for a movement to proceed into that section. (49CFR236)

Traffic Management Coordinator: A traffic management specialist resident at the Air Route Traffic Control Center (ARTCC) Traffic Management Unit (TMU) providing coordination between the national level central flow control function of the ATCCC and local (ARTCC) controllers. (FAA8)

Traffic Management Specialist: Specialist resident at the Air Traffic Control Command Center (ATCCC) who coordinates between local traffic management specialists at ARTCCs and manages flow control operations. (FAA8)

Traffic Management Unit (TMU): A non-control, coordination position at the Air Route Traffic Control Center (ARTCC) connected to the central flow control function at the ATCCC and responsible for dissemination of flow control information at the local level. (FAA8)

Traffic Pattern: The traffic flow that is prescribed for aircraft landing at, taxiing on, or taking off from, an airport. (14CFR1)

Traffic Separation Scheme: Area of water with lanes designated to separate opposing streams of vessel traffic. (DOI4)

Traffic Violation: See Serious Traffic Violation.

Trafficway: That part of a trafficway designed, improved, and ordinarily used for motor vehicle travel. (NHTSA3)

Trafficway Class: A classification of highways based on a route sign. (NHTSA1)

Trail: A cleared path, beaten track, or improved surface, as through woods or wilderness, not usually trafficked by vehicles because of width, seasonal conditions, or access restrictions. (DOI3)

Trail Dike: A dike of wooden pile construction or rock that extends usually from the riverbank outward toward the channel and trails downstream so as to direct the flow of water into the channel. Trail dikes help maintain the channel by keeping it swept by the directional currents. (TNDOT1)

Trailer: A motor vehicle with or without motive power, designed for carrying persons or property and for being drawn by another motor vehicle. (49CFR571) (ATA2)

Trailer Converter Dolly: A trailer chassis equipped with one or more axles, a lower half of a fifth wheel and a drawbar. (49CFR571)

Trailer On a Flat Car/Container On a Flat Car (TOFC/COFC): (See also Intermodal) Often referred to as intermodal service. (AAR1)

Trailer-On-Flatcar (TOFC): (See also Intermodal) Transportation of containers on the chassis of railroad flatcars. (MARAD1)

Trailership: A vessel, other than a carfloat, specifically equipped to carry motor transport vehicles and fitted with installed securing devices to tie down each vehicle. The term trailership includes Roll-on/Roll-off (RO/ RO) vessels. (49CFR171)

Trailing Movement: The movement of a train over the points of a switch which face in the direction in which the train is moving. (49CFR236)

Trailing Point Switch: A switch, the points of which face away from traffic approaching in the direction for which the track is signaled. (49CFR236)

Train: See also Locomotive, Rail, Railway, Railroad.

Train: One or more engines coupled with one or more rail cars, except during switching operations or where the operation is that of classifying and assembling rail cars within a railroad yard for the purpose of making or breaking up trains. (49CFR171)

Train: A locomotive unit or locomotive units coupled, with or without cars, involved in a railroad operation conducted on a main track. It does not include yard movements. (49CFR221) (49CFR236) (FRA3)

Train: A unit of equipment or a combination of units of equipment (including light locomotives) in condition for movement over tracks by self-contained motor equipment. (49CFR245)

Train: A locomotive unit or locomotive units coupled, with or without cars and with or without markers displayed. Included in this definition are those trains consisting entirely of self-propelled units designed to carry passengers and/or freight traffic. (FRA2) (FRA4)

Train Accident: Any collision, derailment, fire, explosion, act of God, or other event involving the operation of on-track equipment and resulting in reportable damage to track or on-track equipment above an established dollar threshold. (FRA2) (FRA4)

Train Berth: In rail operations, the space designated for a train of given length to occupy when it is stopped at a station platform, in a terminal, on a transfer track, or at some other designated place. (TRB1)

Train Density: 1) The number of trains that can be operated safely over a segment of railroad in each direction during a 24-hr. period. 2) The average number of trains that pass over a specified section of railroad in a specified period. (TRB1)

Train Hour: The elapsed time of a road freight train between the time of leaving the initial terminal and the time of arrival at the final terminal, including train switching at the time of arrival at the final terminal, including train switching at way stations and delays on road. (AAR1)

Train Incident: Any event involving the movement of railroad on-track equipment that results in a death, a reportable injury, or a reportable illness, but in which railroad property damage does not exceed the reporting threshold. (FRA3) (FRA4)

Train Mile: The movement of a train a distance of one mile measured by the distance between terminals and/or stations and includes yard switching miles, train switching miles, and work train miles, Yard switching miles may be computed on any reasonable, supportable, and verifiable basis. In the event actual mileage is not computable by other means, yard switching miles may be computed at the rate of 6 mph for the time actually engaged in yard switching service. (49CFR245)

Train or Yard Crew: One or more railroad employees assigned a controlling locomotive, under the charge and control of one crew member; called to perform service covered by Section 2 of the Hours of Service Act; involved with the train or yard movement of railroad rolling equipment they are to work with as an operating crew; reporting and working together as a unit that remains in close contact if more than one employee; and subject to the railroad operating rules and program of operational tests and inspections required in 49 CFR 217.9 and 217.11. (49CFR218)

Train order: Mandatory directives issued as authority for the conduct of a railroad operation outside of yard limits. (49CFR221)

Train-Mile: A unit of comparative measure equal to the movement of one train for a distance of one mile. (FRA3)

Training (Instructional): Any use of an aircraft for the purpose of formal instruction with the flying instructor aboard, or with the maneuvers on the particular flight, specified by the flight instructor; excludes proficiency flying. (FAA10)

Trainmen: Persons employed as engineers and motormen, firemen and helpers, conductors, brakemen and flagmen engaged in passenger, freight, yard or work service and train baggagemen. Prior to 1984 this category did not include hostlers. The Interstate Commerce Commission revised the occupational groupings in 1984 and now includes hostlers in the train and engine category. (FRA3)

Trainship: A vessel other than a rail car ferry or carfloat, specially equipped to transport railroad vehicles, and fitted with installed securing devices to tie down each vehicle. (49CFR171)

Tramp: An oceangoing vessel that does not operate along a definite route or on a fixed schedule, but rather calls at any port where cargo is available. (TNDOT1)

Tramp Line: An ocean carrier company operating tramp steamers not on regular runs or schedules. (MARAD2)

Tramway: Another name for "light rail." (APTA1)

TRANSCAD: Transportation Computer Assisted Design (MTMC1)

TRANSCOM: Transportation Operations Coordinating Committee (FHWA14)

TRANSCOM: United States Transportation Command (MTMC1)

Transfer Capability: The overall capacity of interregional or international power lines, together with the associated electrical system facilities, to transfer power and energy from one electrical system to another. (DOE5)

Transfer Center: A fixed location where passengers interchange from one route or vehicle to another. (APTA1)

Transfer Charge: An extra fee charged for a transfer to use when boarding another transit vehicle to continue a trip. (APTA1)

Transfer of Control: The action whereby control responsibility for an aircraft is transferred from one controller to another. (FAA8)

Transfer Piping: A system of permanent and temporary piping used for transferring hazardous fluids between any of the following: liquefaction process facilities, storage tanks, vaporizers, compressors, cargo transfer systems, and facilities other than pipeline facilities. (49CFR193)

Transfer System: Includes transfer piping and cargo transfer system. (49CFR193)

Transferring Controller/Facility: A controller/facility transferring control of an aircraft to another controller/facility. (FAA8)

Transformer: An electrical device for changing the voltage of alternating current. (DOE5)

Transit: Another name for "public transportation." (APTA1)

Transit: A partial or complete upbound or downbound passage of a vessel through one or more locks of a Seaway canal. (SLSDC1)

Transit Bus: (See also Intercity Bus, Motor Bus, Motorbus, School and Other Nonrevenue Bus) A bus designed for frequent stop service with front and center doors, normally with a rear-mounted diesel engine, low-back seating, and without luggage storage compartments or rest room facilities. Includes motor bus and trolley coach. (APTA1) (DOE6)

Transit Mall: A type of exclusive right-of-way reserved for transit vehicles in revenue service and pedestrian traffic. (FTA1)

Transit Mode: (See also Rail Mode, Rapid Rail, Rapid Transit Rail, Transit Railroad, Transit Railway) Generally defined as urban and rural public transportation services including commuter trains, ferry service, heavy rail (rapid rail) and light rail (streetcar) transit systems, and local transit buses and taxis. (BTS1)

Transit of An Inland Waterways Transport (IWT) Vessel: Any laden or unladen IWT vessel which has entered and left the country at different points by whatever means of transport provided the total journey within the country was by inland waterway and that there has been no loading or unloading operation in the country. (TNDOT1)

Transit Property: All facilities which are directly controlled by a transit agency (agency is responsible for cleaning or maintaining) or provided to a transit agency for its use by another public or private entity (formal/informal agreement with the owner wherein services or facilities are provided to benefit the transit agency). This includes stations, exclusive right-of-ways, bus stops, and maintenance facilities. (FTA1)

Transit Property Damage: Any damage to transit property that requires the repair or replacement of transit agency vehicles or facilities (track, signals, buildings) to a state equivalent to that which existed prior to the incident. (FTA1)

Transit Railroad: (See also Rail Mode, Rapid Rail, Rapid Transit Rail, Transit Mode, Transit Railway) Includes heavy and light transit rail. Heavy transit rail is characterized by exclusive rights-of-way, multi-car trains, high speed rapid acceleration, sophisticated signaling, and high platform loading. Also known as subway, elevated railway, or metropolitan railway (metro). Light transit rail may be on exclusive or shared rights-of-way, high or low platform loading, multi-car trains or single cars, automated or manually operated. In generic usage, light rail includes streetcars, trolley cars, and tramways. (DOE6)

Transit Railway: (See also Rail Mode, Rapid Rail, Rapid Transit Rail, Transit Mode, Transit Railroad) Suburban and urban railway (including light rail such as trolleys, cable cars and car lines) used only for transporting people. (DOI3)

Transit System: An organization (public or private) providing local or regional multi-occupancy-vehicle passenger service. Organizations that provide service under contract to another agency are generally not counted as separate systems. (APTA1)

Transit Trip: A one-way trip by a transit vehicle in revenue service starting at one terminal point of a route and ending at another terminal point. A round trip is counted as two separate trips. In the case where the route is a pure loop involving entirely different streets and pick-up points, and where there is no logical way to identify the terminal points, then traversing of the loop can be regarded as a single trip. (FTA1)

Transit Zones: A form of free trade zone. They are ports of entry in coastal countries that are established as storage and distribution centers for the convenience of a neighboring country lacking adequate port facilities or access to the sea. A transit zone is administered so that goods in transit to or from the neighboring country are not subject to the customs duties, import controls or many of the entry and exit formalities of the host country. (USTTA1)

Transitway: Another name for "High-Occupancy Vehicle Lane." (APTA1)

Transitway: A dedicated right-of-way, most commonly in a mall, that is used by transit units (vehicles or trains), usually mixed with pedestrian traffic. (TRB1)

Transmission Gas Company: A company which obtains at least 90 percent of its gas operating revenues from sales for resale and/or transportation of gas for others and/or main line sales to industrial customers and classifies at least 90 percent of mains (other than service pipe) as field and gathering, storage and/or transmission. (AGA1)

Transmission Network: A system of transmission or distribution lines so cross-connected and operated as to permit multiple power supply to any principal point. (DOE5)

Transmission Pipeline: Pipelines (mains) installed for the purpose of transmitting gas from a source or sources of supply to one or more distribution centers, or to one or more large-volume customers, or a pipeline installed to interconnect sources of supply. In typical cases, transmission lines differ from gas mains in that they operate at higher pressures, are longer, and the distance between connections is greater. (AGA1)

Transmission Type: The transmission is the part of a vehicle that transmits motive force from the engine to the wheels, usually by means of gears for different speeds using either a hydraulic "torque-converter" (automatic) or clutch assembly (manual). On front-wheel drive cars, the transmission is often called a "transaxle". Fuel efficiency is usually higher with manual rather than automatic transmissions, although modern, computer-controlled automatic transmissions can be efficient. (DOE4) (DOE5)

Transmission Types: A3-Automatic three speed, A4-Automatic four speed, A5-Automatic five speed, L4-Automatic lockup four speed, M5-Manual five speed. (DOE6)

Transponder: A piece of equipment which, when set upon a specific radio frequency, emits a directional signal of its own and enables the receiver to track or monitor the truck's location. (BOC3)

Transponder: The airborne radar beacon receiver/transmitter portion of the Air Traffic Control Beacon System that automatically receives radio signals from interrogators on the ground and selectively replaces with specific reply pulse-on-pulse group only those interrogations being received on the mode to which it is set to respond. Each aircraft transponder is capable of replying to 4,096 codes as selected by the pilot. Provides the air traffic controller positive location and, in some cases, altitude information. (FAA6)

Transport: See also Transportation, Travel, Trip.

Transport: Movement of natural, synthetic, and/or supplemental gas between points beyond the immediate vicinity of the field or plant from which produced except 1) For movements through well or field lines to a central point for delivery to a pipeline or processing plant within the same state or 2) Movements from a citygate point of receipt to consumers through distribution mains. (DOE5)

Transport Airport: An airport designed, constructed and maintained to serve airplanes in Aircraft Approach Category C and D. (FAA12)

Transport Related Expenses: All expense items applicable to the generation of transport-related revenues. (BTS4)

Transport Revenue: Revenues from the transportation by air of all classes of traffic in scheduled and nonscheduled services. (BTS4)

Transport Vehicle: A cargo-carrying vehicle such as an automobile, van, tractor, truck, semitrailer, tank car or rail car used for the transportation of cargo by any mode. Each cargo carrying body (trailer, rail car, etc.) is a separate transport vehicle. (49CFR171)

Transportation: See also Transport, Travel, Trip.

Transportation Administration and Support: All activities associated with transportation administration, revenue vehicle movement control and scheduling including supervision and clerical support. (FTA1)

Transportation Agreement: Any contractual agreement for the transportation of natural and/or supplemental gas between points for a fee. (DOE5)

Transportation Bill: The bill refers to the market value of all purchases of transportation services and facilities; it includes all domestic expenditures made by an economy for transportation purposes. Although the transportation bill does not reflect several significant non-market costs, it is a useful indicator of a country's transportation expenditures, and transportation analysts closely follow changes in the bill and its components. (BTS1)

Transportation Brokerage: 1) Coordination of transportation services in a defined area. The transportation broker may centralize vehicle dispatch, record keeping, vehicle maintenance, and other functions under contractual arrangement with agencies, municipalities, and other organizations. 2) A method of matching travelers with a variety of transportation providers through use of central dispatching and administrative facilities. (TRB1)

Transportation Improvement Program: As stated in FHWA-UMTA joint regulations that govern transportation programming, a prioritized program of transportation projects to be implemented in appropriate stages over several years (i.e., 3-5 yr.). The projects are recommended from those in the transportation systems management element and the long-range element of the planning process. This program is required as a condition for a locality to receive federal transit and highway grants. (TRB1)

Transportation Industry: Those establishments or parts of establishments that build transportation facilities and equipment; operate transportation facilities; provide for-hire transportation services for individuals, households, businesses, or government agencies; provide supporting in-house transportation for a business or government agency; arrange transportation services for individuals, households, businesses or government agencies; provide supporting services necessary to the provision of transportation services; or administer transportation programs. This definition includes a diverse cross section of the economy, such as automobile manufacturers, railroads, travel agents, school district bus operators, port authorities, gas stations, and the trucking fleets of major grocery chains. (BTS2)

Transportation Interface and Reporting System (TIRES): Processes all income earned and expenses incurred in operating the Interagency Fleet Management System. TIRES produces profit and loss reports as well as other detail reports for output to FSS. Sales transactions are generated for input into the Automotive Billing (AUTOBILL) module. (GSA2)

Transportation Management Area (TMA): An urbanized area with a population over 200,000 (as determined by the latest decennial census) or other area when TMA designation is requested by the Governor and the MPO (or affect local officials), and officially designated by the Administrators of the FHWA and the FTA. The TMA designation applies to the entire metropolitan planning area(s). (23CFR500)

Transportation Research Information Services (TRIS): The Transportation Research Board (TRB)-maintained computerized storage and retrieval system for abstracts of ongoing and completed research, development, and technology transfer (RD&T) activities, including abstracts of RD&T reports and articles. (23CFR420)

Transportation Sector: The transportation sector consists of private and public vehicles that move people and commodities. Included are automobiles, trucks, buses, motorcycles, railroads and railways (including streetcars), aircraft, ships, barges, and natural gas pipelines. (DOE3)

Transportation Sector: Consists of both private and public passenger and freight transportation, as well as government transportation, including military operations. (DOE6)

Transporter: The party or parties, other than buyer or seller, owning the facilities by which gas or liquefied natural gas (LNG) is physically transferred between buyer and seller. (DOE5)

Transshipment: The transfer of goods from one carrier to another. (TNDOT1)

Transshipment: (See also Intermodal) A method of ocean transportation whereby ships off-load their oil cargo to a deepwater terminal, floating storage facility, temporary storage, or to one or more smaller tankers from which or in which the oil is then transported to a market destination. (DOE5)

Trap Circuit: A term applied to a circuit used where it is desirable to provide a track circuit but where it is impracticable to maintain a track circuit. (49CFR236)

Travel: See also Transport, Transportation, Trip.

Travel Advisory Program: The Department of State manages a travel advisory program which publicizes 1) Travel warnings which are issued when State decides to recommend that Americans avoid travel to a certain country and 2) Consular information sheets, issued for every country, which advise travelers of health concerns, immigration and currency regulations, crime and security conditions, areas of unrest or instability, and the location of U.S. embassies or consulates. (USTTA1)

Travel Agencies: Establishments primarily engaged in furnishing travel information and acting as agents in arranging tours, transportation, rental of cars, and lodging for travelers. (BOC1)

Travel Day: A 24-hour period from 4:00 a.m. to 3:59 a.m. designated as the reference period for studying trips and travel by members of a sampled household. (FHWA3)

Travel Day Trip: A travel day trip is defined as any one-way travel from one address (place) to another by any means of transportation (e.g., private motor vehicle, public transportation, bicycle, or walking). When travel is to more than one destination, a separate trip exists each time one or both of the following criteria is satisfied: the travel time between two destinations exceeds 5 minutes, and/or the purpose for travel to one destination is different from the purpose for travel to another. The one exception is travel within a shopping center or mall. It is to be considered travel to one destination, regardless of the number of stores visited. (FHWA3)

Travel Density: The average number of vehicle miles driven on a section of highway each day divided by the length of the section in miles. It is expressed as a number of vehicles and may be referred to as average daily traffic (ADT). (FHWA1)

Travel Period: The 13 days immediately preceding the travel day and the designated travel day for a sampled household, for a total of 14 days. (FHWA3)

Travel Period Trip: A travel period trip is one-way to a destination which is 75 miles or more from home with a return home trip during the 14-day travel period. Travel to the destination is counted as one trip and travel to return home is counted as another trip. For example, a person living in Denver flies to San Francisco, stays one week, and returns to Denver during the 14-day travel period. This would be counted as two travel period trips-one outgoing and one return. The only time a travel period trip would not have a return trip collected is when the respondent moves his/her residence. (FHWA3)

Travel Surface: The type of material which forms the travel surface. Codes as follows: AG-aggregate, B-bituminous, C-concrete, CA-caliche, N-natural (graded and drained), NU- natural unimproved (wheel tracks, O.R.V.). (DOI2)

Traveler: A person who stays for a period of less than 1 year in a country of which he or she is not a resident. Military and other government personnel and their dependents stationed outside their country of residence are not considered travelers, regardless of the length of their stay abroad; they are considered to have remained within the economy of their home country. The definition of travelers also excludes owners or employees of business enterprises who temporarily work abroad in order to further the enterprise's business, but intend to return to their country of residence within a reasonable period of time. (USTTA1)

TRB: Transportation Research Board (FHWA7) (MTMC1) (NHTSA6)

Tread: Distance between the centers of tires at the points where they contact the road surface. Duals are measured from the center of dual wheels. (TII1) (TII2)

Treasury Stock: The cost of reacquired capital stock issued by the air carrier and not retired or cancelled. (BTS4)

Trespasser: Any person whose presence on railroad property, used in railroad operation, is prohibited or unlawful. (FRA3)

Trespassers (Class E): Persons who are on that part of railroad property used in railroad operation and whose presence is prohibited, forbidden, or unlawful. (FRA2)

Triaxle: Three axle tractor or trailer. (ATA1)

Trip: See also Transport, Transportation, Travel.

Trip: A movement of a locomotive over all or any portion of automatic train stop, train control or cab signal territory between the terminals for that locomotive; a movement in one direction. (49CFR236)

Trip Assignment: In planning, a process by which trips, described by mode, purpose, origin, destination, and time of day, are allocated among the paths or routes in a network by one of a number of models. (TRB1)

Trip Distribution: In planning, the process of estimating movement of trips between zones by using surveys or models. (TRB1)

Trip Generation: In planning, the determination or prediction of the number of trips produced by and attracted to each zone. (TRB1)

Trip Pilot: A pilot hired for one trip only. (TNDOT1)

Trip Type: "Intercity" or "city." Trip type is often subdivided into "charter" or "scheduled" service. (FHWA2)

Trip Type: "Local" or "over-the-road." (FHWA4)

Triple Truck: A truck-tractor which pulls 3 trailers. (BOC3)

TRIPS: Transportation Intelligent Planning System (MTMC1)

TRIS: Transportation Research Information Service (BTS7)

TRO: Trip Reduction Ordinance (MOCD)

Trolley Car: Another name for "light rail." (APTA1)

Trolley Coach: Rubber-tired electric transit vehicle, manually-steered, propelled by a motor drawing current, normally through overhead wires, from a central power source not on board the vehicle. (DOE6)

Trolley Replica: A type of vehicle having the appearance of a trolley or streetcar but has rubber tires and is powered by a diesel, gasoline, propane or alternative fuel engine contained within the vehicle. Trolley replicas are classified as motor bus mode in the NTD system. (FTA1)

Trolleybus: Rubber-tired passenger vehicles operating singly on city streets. Trolleybuses are driven electrically with the power being drawn from an overhead electric line via trolleys. (FTA1)

Trolly Brake: A hand valve used to operate the trailer brakes independently of tractor brakes. (ATA1)

TRRL: Transport and Road Research Laboratory (FHWA8)

TRSA: Terminal Radar Service Area (FAA4)

Truck: See also Motor Vehicle, Semi, Semitrailer, Tractor Trailer, Trucking.

Truck: Any self-propelled motor vehicle except a truck tractor, designed and/or used for the transportation of property. (49CFR390)

Truck: A motor vehicle with motive power, except a trailer, designed primarily for the transportation of property or special purpose equipment. (49CFR571)

Truck: A motor vehicle designed to carry an entire load. It may consist of a chassis and body; a chassis, cab and body; or it may be of integral construction so that the body and chassis form a single unit. (ATA2)

Truck Crash: (See also Accident, Crash, Collision, Incident) A motor vehicle crash in which at least one medium or heavy truck is involved. (NHTSA4)

Truck Inventory and Use Survey: Survey designed to collect data on the characteristics and operational use of the nation's truck population. It is conducted every five years by the U.S. Bureau of the Census. Surveys were conducted in 1963, 1967, 1972, 1977, 1982, 1987 and 1992. (DOE6)

Truck Jockey: Truck driver. (ATA1)

Truck Size Classification: U.S. Bureau of the Census has categorized trucks by gross vehicle weight (GVW) as follows: 1) Light-Less than 10,000 pounds GVW 2) Medium-10,001 to 20,000 pounds GVW 3) Light-heavy-20,001 to 26,000 pounds GVW 4) Heavy-heavy-26,001 pounds GVW or more. (DOE6)

Truck Tractor: A truck or self-propelled motor vehicle designed and/or used primarily for drawing other motor vehicles and not so constructed as to carry a load other than a part of the weight of the vehicle and the load so drawn. (49CFR390) (49CFR571)

Truck-Tractor Semitrailer-Semitrailer: The two trailing units are connected with a "B-train" assembly. The B-train assembly is a rigid frame extension attached to the rear frame of a first semitrailer which allows for a fifth wheel connection point for the second semitrailer. This combination has one less articulation point than the conventional "A dolly" connected truck-tractor semitrailer-semitrailer combination. (23CFR658)

Truck-Trailer Boat Transporter: A boat transporter combination consisting of a straight truck towing a trailer using typically a ball and socket connection. The trailer axle(s) is located substantially at the trailer center of gravity (rather than the rear of the trailer) but so as to maintain a downward force on the trailer tongue. (23CFR658)

Trucking: See also Semi, Semitrailer, Tractor, Tractor-Semitrailer, Truck.

Trucking (Except Local): Establishments primarily engaged in furnishing "over-the-road" trucking services or trucking services and storage services, including household goods either as common carriers or under special or individual contracts or agreements, for freight generally weighing more than 100 pounds. Such operations are principally outside a single municipality, outside one group of contiguous municipalities, or outside a single municipality and its suburban areas. (BOC1)

Truckload: Quantity of freight required to fill a truck. When used in connection with freight rates, the quantity of freight necessary to qualify a shipment for a truckload rate. Usually in excess of 10,000 pounds. (ATA2)

True Airspeed: The airspeed of an aircraft relative to undisturbed air. True airspeed is equal to equivalent airspeed multiplied by (pO/p)l/2. (14CFR1)

Trunking: A casing used to protect electrical conductors. (49CFR236)

Trunnion: A cylindrical projection supporting a revolving part. (49CFR236)

Trust Fund: Trust funds are funds that are designated by law as trust funds. They are usually financed by earmarked collections. A trust fund must use its income for the purposes designated by law, but it is not required to spend them all in the same period they are collected. The five transportation-related federal trust funds are highways, which includes highway and transit accounts; airports and airways; aquatic resource, which is of interest because of the boat safety account; harbor maintenance, and inland waterways. There is also a pipeline safety fund, however, it is not a trust fund. (BTS3)

TSA: Taxiway Safety Area (FAA12)

TSAR: Transportation Statistics Annual Report (BTS2)

TSCS: Transportation System Capability Study (MTMC1)

TSI: Transportation Safety Institute (OFR1) (RSPA1)

TSM: Transportability Summary Manual (MTMC1)

TSM: Transportation System Management (TRB1)

TSO: Technical Standard Order (FAA17)

TSRC: Transportation Systems Review Committee (MTMC1)

TSS: Track Suspension System (MTMC1)

TTCE: Transportation Terminal Command Europe (MTMC1)

TTFE: Transportation Terminal Command Far East (MTMC1)

TTI: Texas Transportation Institute (FTA4)

TTMA: TRACON Traffic Management Advisor (FAA17)

TTU: Transportation Terminal Unit (MTMC1)

Tug: See also Towboat.

Tug: A small but powerful vessel designed for moving larger vessels or for towing barges. Also called "towboat" or "pushboat". (TNDOT1)

Tug and Barge Combinations: The assessment of tolls requires tugs and barges in common transit to be considered as one unit. In this report the number of transits shown under this category represents the number of combined passages plus the number of individual tugs transiting the Seaway. (SLSDC1)

TUL: Tulsa International Airport (FAA11)

Tunnel: An underground or underwater passage. (DOI4)

Tunnel: 1) An enclosed passageway, as for trains, automobiles, and so on, through or under an obstruction, such as a city, mountain, river, or harbor. 2) An underground passage. (TRB1)

Tunnel Entrance: Opening that affords entry to an underground or underwater passage. (DOI3)

Turn a Tow: To exchange tows, as when a towboat meets another towboat belonging to the same company proceeding in the opposite direction and they exchange their entire tows and return in the same direction from whence they came. (TNDOT1)

Turn Around: A truck that leaves from and returns to the same terminal. (ATA1)

Turn Signals: Lamps used to indicate a change in direction by emitting a flashing light on the side of a motor vehicle towards which a turn will be made. (49CFR393)

Turning Basin: An area of water or enlargement of a channel used for the turning around of vessels. (TNDOT1)

Turning Roadway: A connecting roadway between two intersection legs that are at the same grade. (DOI3)

Turning Shipping Lane: Area designated as a place for ships to turn. (DOI3)

Turnout: 1) In rail transportation, the assembly of a switch and a frog with closure rails by which rolling stock or trains can travel from a track onto either one of two diverging tracks; also known as a track switch. 2) A short side track or passage that enables trains, automobiles, and similar vehicles to pass one another. 3) A short passing lane on a highway. (TRB1)

Turnpike Double: A combination vehicle consisting of a tractor and two trailers of 45 to 48 feet. (ATA2)

Turntable: A circular, horizontal, rotating platform equipped with a railway track, used for turning locomotives, as in a roundhouse. (DOI3) (DOI4)

TUS: Tucson International Airport (FAA11)

TVOR: Terminal VOR (FAA17)

TVT: Traffic Volume Trends (BTS7)

TW: Taxiway (FAA12)

TWDR: Terminal Weather Doppler Radar (FAA17)

TWEB: Transcribed Weather Broadcast (FAA4)

TWH: Terawatt Hour (DOE7)

Twin Screw: A truck or tractor with two rear axles, both driven by the engine. (ATA1)

Twin Trailer: A short semitrailer (under 29 feet) designed to be operated as part of a combination vehicle with a tandem trailer of similar length. (ATA2)

Two Axle Four Tire Truck: A motor vehicle consisting primarily of a single motorized device with two axles and four tires. (DOE6)

Two-Speed Axle: A rear axle with two ratios and a mechanism for selecting one or the other ratio, usually available with a standard type transmission. A double reduction axle which does not have a mechanism for selecting ratios is not a 2-speed axle. (TII1) (TII2)

TWU: Transport Workers Union (TRB1)

Type: 1) As used with respect to the certification, ratings, privileges, and limitations of airmen, means a specific make and basic model of aircraft, including modifications thereto that do not change its handling or flight characteristics. Examples include: DC-7, 1049, and F-27; and 2) As used with respect to the certification of aircraft, means those aircraft which are similar in design. Examples include: DC-7 and DC-7C; 1049G and 1049H; and F-27 and F27F; and 3) As used with respect to the certification of aircraft engines means those engines which are similar in design. For example, JT8D and JT8D7 are engines of the same type, and JT9D-3A and JT9D-7 are engines of the same type. (14CFR1)

Type of Drive: Refers to which wheels the engine power is delivered to, the so-called "drive wheels." Rear-wheel drive, has drive wheels on the rear of the vehicle. Front-wheel drive, a newer technology, has drive wheels on the front of the vehicle. Four-wheel drive uses all four wheels as drive wheels, and is found mostly on Jeep-like vehicles and trucks, though it is becoming increasingly more common on station wagons and vans. (DOE4) (DOE5)

Type of Occurrence: (See also Accident) The highest level of an accident classification mechanism known as the sequence of events. (NTSB1) (NTSB2)

Type of Primary Service: The dominant type of service the respondent uses at the service station. Response categories include Full-Service Pumps, "Self-or Mini-Service Pumps," or " Both Equally." Mini Service is provided when attendants pump the vehicle fuel but do not provide any other service, such as checking the tire pressure or washing windshields. (DOE4)

Types of Goods Carried By Inland Waterways: The categories of goods carried by inland waterways are those defined by the NST/R (Standard Goods Nomenclature for Transport Statistics/revised EUROSTAT) or CSTE (UN-ECE Commodity Classification for Transport Statistics in Europe) nomenclatures. (TNDOT1)

TYS: McGhee Tyson Airport (FAA11)

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