You are here


H Point: The mechanically hinged hip point of a manikin which simulates the actual pivot center of the human torso and thigh, described in Society of Automotive Engineers (SAE) Recommended Practice J826, "Manikins for Use in Defining Vehicle Seating Accommodations," November 1962. (49CFR571)

H T&I: House - Transportation and Infrastructure Committee (FHWA18)

H/WSTAG: Hazardous Waste and Substance Technical Advisory Group (FHWA18)

HAA: Height Above Airport (FAA20)

HABS: Historic American Building Survey (FHWA18)

HACS: Hazard Assessment Computer System (BTS7)

HAD: Office of the Associate Administrator for Administration (FHWA18)

HAL: Height Above Landing (FAA20)

Hand Operated Switch: A non-interlocked switch which can only be operated manually. (49CFR236)

Handling: Physically moving cargo between point-of-rest and any place on the terminal facility, other than the end of ship's tackle. (MARAD1)

Handoff: A Controller action taken to transfer the radar identification of an aircraft from one Controller to another if the aircraft will enter the receiving Controller's airspace and radio communications with the aircraft will be transferred. (FAA4) (FAA8)

Handy Line: Small line used to throw between separated barges or boat and shore, (i.e., heaving line). (TNDOT1)

HAR: Highway Advisory Radio (FHWA19)

Harbor: An area of water where ships, planes, or other watercraft can anchor or dock. (DOI4)

Harbor Line: An imaginary line, or plane, approximately parallel to a riverbank, or shore, shoreward of which any marine structure may be erected without the authority of a formal federal navigation permit. Also called harbor line. Established by act of Congress. (TNDOT1)

Harbor Maintenance Trust Fund: Accounts that are specifically designated by law to carry out specific purposes and programs. Trust Funds are usually financed with earmarked tax collections. (BTS11)

Harbor Master: An officer who attends to the berthing, etc., of ships in a harbor. (MARAD2)

Harmonized System of Codes: An international goods classification system for describing cargo in international trade under a single commodity coding scheme. This code is a hierarchically structured product nomenclature containing approximately 5,000 headings and subheadings. (MARAD2)

HARS: High Altitude Route System (FAA17)

HAS: Office of the Associate Administrator for Safety (FHWA18)

HAT: Height Above Touchdown (FAA20)

Haulage Cost: Cost of loading ore at a mine site and transporting it to a processing plant. (DOE5)

Hauling Post Holes: Driving an empty truck or trailer. (ATA1)

Have Numbers: Used by pilots to inform Air Traffic Control (ATC) that they have received runway, wind, and altimeter information only. (FAA4)

Hawser: A tow line. (TNDOT1)

Hazard to Navigation: For the purpose of 49CFR195, a pipeline where the top of the pipe is less than 12 inches below the seabed in water less than 15 feet deep, as measured from the mean low water. (49CFR195)

Hazard Warning Signal: Lamps that flash simultaneously to the front and rear, on both the right and left sides of a commercial motor vehicle, to indicate to an approaching driver the presence of a vehicular hazard. (49CFR393)

Hazard Zone: One of four levels of hazard (Hazard Zones A through D) assigned to gases, as specified in 49 CFR 173.116(a), and one of two levels of hazards (Hazard Zones A and B) assigned to liquids that are poisonous by inhalation, as specified in 49 CFR 173.133(a) of this subchapter. A hazard zone is based on the LC50 value for acute inhalation toxicity of gases and vapors, as specified in 49 CFR 173.133(a). (49CFR171)

Hazard Zone: An area identified as a danger to maritime navigation. (DOI3)

Hazardous Area Reporting Service: Flight monitoring for Visual Flight Rules (VFR) aircraft crossing large bodies of water, swamps, and mountains. This service is provided for the purpose of expeditiously alerting Search and Rescue (SAR) facilities when required. Radio contacts are desired at least every 10 minutes. If contact is lost for more than 15 minutes, SAR will be alerted. (FAA8)

Hazardous Goods: The categories of hazardous goods carried by inland waterways are those defined by the European Provisions concerning the International Carriage of Dangerous Goods by Inland Waterways. (TNDOT1)

Hazardous Inflight Weather Advisory Service: Continuous recorded hazardous inflight weather forecasts broadcasted to airborne pilots over selected very high frequency omnidirectional (VOR) outlets defined as an HIWAS BROADCAST AREA. (FAA4)

Hazardous Liquid: Liquefied Natural Gas (LNG) or a liquid that is flammable or toxic. (49CFR193)

Hazardous Material: Any toxic substance or explosive, corrosive, combustible, poisonous, or radioactive material that poses a risk to the public's health, safety, or property-particularly when transported in commerce. (BTS11)

Hazardous Material Employee: A person who is employed by a HAZMAT employer and who in the course of employment directly affects hazardous materials transportation safety. This term includes an owner-operator of a motor vehicle which transports hazardous materials in commerce. This term includes an individual, including a self-employed individual, employed by a HAZMAT employer who, during the course of employment: 1) Loads, unloads, or handles hazardous materials; 2) Tests, reconditions, repairs, modifies, marks, or otherwise represents containers, drums, or packagings as qualified for use in the transportation of hazardous materials; 3) Prepares hazardous materials for transportation; 4) Is responsible for safety of transporting hazardous materials; or 5) Operates a vehicle used to transport hazardous materials. (49CFR171)

Hazardous Material Employer: A person who uses one or more of its employees in connection with: transporting hazardous materials in commerce; causing hazardous materials to be transported or shipped in commerce; or representing, marking, certifying, selling, offering, reconditioning, testing, repairing, or modifying containers, drums, or packagings as qualified for use in the transportation of hazardous materials. This term includes an owner-operator of a motor vehicle which transports hazardous materials in commerce. This term also includes any department, agency, or instrumentality of the United States, a State, a political subdivision of a State, or an Indian tribe engaged in an activity described in the first sentence of this definition. (49CFR171)

Hazardous Material Residue: The hazardous material remaining in a packaging, including a tank car, after its contents have been unloaded to the maximum extent practicable and before the packaging is either refilled or cleaned of hazardous material and purged to remove any hazardous vapors. (FRA2)

Hazardous Substance: A material, and its mixtures or solutions, that is identified in the appendix to 49 CFR 172.101, List of Hazardous Substances and Reportable Quantities, of this title when offered for transportation in one package, or in one transport vehicle if not packaged, and when the quantity of the material therein equals or exceeds the reportable quantity (RQ). This definition does not apply to petroleum products that are lubricants or fuels, or to mixtures or solutions of hazardous substances if in a concentration less than that shown in the table in 49 CFR 171.8 of this title, based on the RQ specified for the materials listed in the appendix to 49 CFR 172.101. (49CFR390)

Hazardous Waste: Any material that is subject to the hazardous waste manifest requirements of the Environmental Protection Agency (EPA) specified in 40 CFR 262 or would be subject to these requirements absent an interim authorization to a State under 40 CFR 123, subpart F. (49CFR171) (49CFR390)

HAZMAT: Hazardous Material (FMCSA1)

HBCU: Historically Black Colleges and Universities (FHWA18)

HBLRTS: Hudson-Bergen Light Rail Transit System (FTA5)

HBRRP: Highway Bridge Replacement & Rehabilitation Program (FHWA18)

HC: Hydrocarbon (BTS11)

HC: Hydrocarbon (DOE6)

HCAADT: Heavy Commercial AADT (FHWA19)

HCAP: High Capacity Carriers (FAA20)

HCAS: Highway Cost Allocation Study (FHWA19)

HCC: Office of the Chief Counsel (FHWA18)

HCM: Office of the Associate Administrator for Corporate Management (FHWA18)

HCM: Highway Capacity Manual (FHWA8)

HCR: Office of the Associate Administrator for Civil Rights (FHWA18)

HCS: Host Computer System (FAA20)

HCS: Highway Capacity Software or Hazard Communication Standards (FHWA18)

HD: Highway Design (FHWA16)

HD: Headway Detection (FHWA19)

HDDV: Heavy Duty Diesel Vehicle (VDOT)

HDLC: Heavy Duty Locking Clip (same as BSLC = Belt Shortening Locking Clip) (NHTSA7)

HDME: NDB with Distance Measuring Equipment (FAA20)

HDQ: FAA Headquarters (FAA20)

HDR: Hardware Discrepancy Report (FAA20)

Head: 1) The product of the water's weight and a usable difference in elevation gives a measurement of the potential energy possessed by water. 2) Marine restroom facility. (DOE5)

Head Impact Area: All nonglazed surfaces of the interior of a vehicle that are statically contactable by a 6.5-inch diameter spherical head form of a measuring device having a pivot point to "top-of-head" dimension infinitely adjustable from 29 to 33 inches in accordance with the procedure explained in 49 CFR 390.5. (49CFR571)

Head Lamps: Lamps used to provide general illumination ahead of a motor vehicle. (49CFR393)

Head Log: The heavily reinforced section at each end of the barges and at the bow of the towboat to take the pressure of pushing the entire tow. (TNDOT1)

Head of Bend: The top or upstream beginning of a bend. (TNDOT1)

Head of Navigation: The furthest (upriver) location on a river deep enough for navigation. (TNDOT1)

Head of Passes: A point near the mouth of the Mississippi River where the three principal distributary passes diverge. It is the point from which river distances are measured. (TNDOT1)

Head On Collision: 1) Refers to a collision where the front end of one vehicle collides with the front-end of another vehicle while the two vehicles are traveling in opposite directions. 2) A collision in which the trains or locomotives involved are traveling in opposite directions on the same track. (FRA2) (NHTSA3)

Head On Landing: Landing in which the bow of the boat only is made fast. (TNDOT1)

Headache Rack: Heavy bulkhead that extends over cab from trailers, usually made of pipe and used in steel hauling. (ATA1)

Header Bar: Rear cross piece on open top trailer. (ATA1)

Header Board: Protective shield at front end of flat bottom trailer to prevent freight from shifting forward. (ATA1)

Headline: Mooring line used in combination to hold a fleet or barge "in". (TNDOT1)

Headwaters: The upper part of a river system, denoting the upper basin and source streams of a river. (DOI4)

Headway: The time interval between transit revenue vehicles passing a specified location. (FTA1)

Heater: Any device or assembly of devices or appliances used to heat the interior of any motor vehicle. This includes a catalytic heater which must meet the requirements of 49 CFR 177.834(1) when flammable liquid or gas is transported. (49CFR393)

Heavy Duty Truck: Truck with a gross vehicle weight generally in excess of 19,500 pounds (class 6-8). Other minimum weights are used by various law or government agencies. (ATA2)

Heavy Hauler Trailer: A trailer with one or more of the following characteristics: 1) Its brake lines are designed to adapt to separation or extension of the vehicle frame; or 2) Its body consists only of a platform whose primary cargo carrying surface is not more than 40 inches above the ground in an unloaded condition, except that it may include sides that are designed to be easily removable and a permanent "front-end structure" as that term is used in 49 CFR 393.106. (49CFR393)

Heavy Lifts: Freight too heavy to be handled by regular ship's tackle. (TNDOT1)

Heavy Rail: High-speed, passenger rail cars operating singly or in trains of two or more cars on fixed rails in separate rights-of-way from which all other vehicular and foot traffic is excluded. (FTA1)

Heavy Rail (Rapid Rail): Transit service using rail cars powered by electricity which is usually drawn from a third rail and usually operated on exclusive rights-of-way. It generally uses longer trains and has longer spacing between stations than light rail. (FTA2)

Heavy Rail (Transit): An electric railway with the capacity to transport a heavy volume of passenger traffic and characterized by exclusive rights-of-way, multicar trains, high speed, rapid acceleration, sophisticated signaling, and high-platform loading. Also known as subway, elevated (railway), or metropolitan railway (metro). (BTS11)

Heavy Rail Passenger Cars: Rail cars with motive capability, driven by electric power taken from overhead lines or third rails, configured for passenger traffic and usually operated on exclusive right-of-way. (FTA1)

HEEP: Highway Engineering Exchange Program (FHWA19)

Height Above Airport: The height of the Minimum Descent Altitude above the published airport elevation. This is published in conjunction with circling minimums. (FAA4)

Height Above Landing: The height above a designated helicopter landing area used for helicopter instrument approach procedures. (FAA4)

Height Above Touchdown: The height of the Decision Height or Minimum Descent Altitude above the highest runway elevation in the touchdown zone (first 3,000 feet of the runway). Height Above Touchdown (HAT) is published on instrument approach charts in conjunction with all straight in minimums. (FAA4)

Height/Decision Altitude: A specified altitude or height (A/H) in the precision approach at which a missed approach must be initiated if the required visual reference to continue the approach has not been established. Note 1: Decision altitude is referenced to mean sea level and decision height is referenced to the threshold elevation. Note 2: The required visual reference means that section of the visual aids or of the approach area which should have been in view for sufficient time for the pilot to have made an assessment of the aircraft position and rate of change of position, in relation to the desired flight path. (FAA4)

HELI: Heliport (FAA20)

Helicopter: A heavier than air aircraft supported in flight chiefly by the reactions of the air on one or more power driven rotors on substantially vertical axes. (FAA4)

Helipad: A small, designated area, usually with a prepared surface, on a heliport, airport, landing/takeoff area, apron/ramp, or movement area used for takeoff, landing, or parking of helicopters. (FAA4)

Heliport: 1) An area of land, water, or structure used or intended to be used for the landing and takeoff of helicopters and includes its buildings and facilities if any. 2) An area, either at ground level or elevated on a structure, that is used for the landing and take-off of helicopters and includes some or all of the various facilities useful to helicopter operations such as: helicopter parking, hangar, waiting room, fueling, and maintenance equipment. (AIA1) (FAA2) (FAA4)

Helistop: A minimum facility heliport, either at ground level or elevated on a structure for the landing and takeoff of helicopters, but without such auxiliary facilities as: waiting room, hangar parking, etc. (AIA1)

HELO: Helicopter (MTMC1)

HELP: Heavy vehicle Electronic License Plate (Crescent) (FHWA19)

HEMS: Helicopter Emergency Medical Service (FAA20)

HEMTT: Heavy Expanded Mobility Tactical Truck (MTMC1)

HEP: Office of the Associate Administrator for Planning, Environment and Realty (FHWA18)

Here She Comes: Term used when another boat appears around a bend. (TNDOT1)


A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z