Search Results - M (365 entries)

M&R: Maintenance and Repair  (MTMC1)

M5: Manual Five Speed  (DOE6)

M85: 85 Percent / 15 Percent Unleaded Gasoline  (BTS8)

MAA: Maximum Authorized Altitude  (FAA4)

MAC: Military Airlift Command  (MTMC1)

Mach Number: The ratio of true airspeed to the speed of sound.  (14CFR1)   (FAA4)

Mach Technique: Describes a control technique used by air traffic control whereby turbojet aircraft operating successively along suitable routes are cleared to maintain appropriate MACH numbers for a relevant portion of the en route phase of flight. The principle objective is to achieve improved utilization of the airspace and to ensure that separation between successive aircraft does not decrease below the established minima.  (FAA4)

Mackinaw Boat: A crudely built flatboat used on the Ohio and Upper Mississippi rivers during the 18th century.  (TNDOT1)

Magazine Vessel: A vessel used for the receiving, storing, or dispensing of explosives.  (49CFR171)

MAGLEV: Magnetic Levitated  (TXDOT)

Magnetic Levitation: A rail transportation system with exclusive right-of-way which is propelled along a fixed guideway system by the attraction or repulsion of magnets on the rails and under the rail cars.  (APTA1)

Mail Revenue: Revenues from the carriage of mail bearing postage for air transportation both U.S. and foreign mail that go by air on priority and nonpriority bases.  (BTS4)

Main: A distribution line that serves as a common source of supply for more than one gas service line.  (AGA1)

Main Deck: The lowest deck on a river steamboat. The main deck supports the vessel's engines and boilers and has space for fuel and cargo.  (TNDOT1)

Main Heating Fuel: Fuel that powers the main heating equipment.  (DOE5)

Main Rotor: The rotor that supplies the principal lift to a rotorcraft.  (14CFR1)

Main Stem: The main portion of navigable channel of a river where more than one channel exists.  (TNDOT1)

Main Track: A track, other than an auxiliary track, extending through yards or between stations, upon which trains are operated by timetable or train order or both, or the use of which is governed by a signal system.  (49CFR218)   (49CFR221)   (49CFR236)   (49CFR245)   (FRA3)

Maintain: 1) Concerning altitude flight level, the term means to remain at the altitude flight level specified. The phrase "climb and" or "descend and" normally precedes "maintain" and the altitude assignment; e.g., "descend and maintain 5,000". 2) Concerning other Air Traffic Control (ATC) instructions, the term is used in its literal sense; (e.g., maintain Visual Flight Rule (VFR)).  (FAA4)

Maintenance: (See also Preventive Maintenance) Inspection, overhaul, repair, preservation, and the replacement of parts, but excludes preventive maintenance.  (14CFR1)

Maintenance: All expenses, both direct and indirect, specifically identifiable with the repair and upkeep of property and equipment.  (BTS4)

Maintenance Control Center (MCC): (See also Preventive Maintenance) Responsible for the oversight of authorization for vehicle repair and authorization and certification of maintenance and repair invoices for Interagency Fleet Management System (IFMS) vehicles within the specified region(s). The MCC also contacts vendors to schedule vehicle services.  (GSA2)

Major Alteration: An alteration not listed in the aircraft, aircraft engine, or propeller specifications that 1) Might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or 2) Done according to accepted practices cannot be done by elementary operations.  (14CFR1)

Major Carrier Group: Air carrier groups with annual operating revenues exceeding $1,000,000,000.  (BTS4)   (BTS5)   (BTS6)   (FAA11)

Major Fuel: Fuels or energy sources such as electricity, fuel oil, liquefied petroleum gases, natural gas, district steam, district hot water, and district chilled water.  (DOE5)

Major Interstate Pipeline Company: A company whose combined sales for resale, including gas transported interstate or stored for a fee, exceeded 50 million thousand cubic feet in the previous year.  (DOE5)

Major Repair: A repair that, if improperly done, might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or that is not done according to accepted practices or cannot be done by elementary operations.  (14CFR1)

Major River: A river that, because of its velocity and vessel traffic, would require a more rapid response in case of a worst case discharge.  (49CFR194)

Make Short Approach: Used by Air Traffic Control (ATC) to inform a pilot to alter his traffic pattern 80 degrees as to make a short final approach.  (FAA4)

Make Up Tow: To assemble barges into a tow.  (TNDOT1)

MALS: Medium Intensity Approach Light System  (14CFR1)

MALSF: Medium Intensity Approach Light System With Sequenced Flashing Lights  (FAA4)

MALSR: Medium Intensity Approach Light System With Rail  (FAA4)   (FAA17)   (FAA19)

Man-Hour: An industrial unit of production reflecting paid labor hours.  (FRA3)

Mandatory Altitude: An altitude depicted on an instrument approach procedure chart requiring the aircraft to maintain altitude at the depicted value.  (FAA4)

Mandatory Use Seat Belt Law: (See also Manual Restraint System, Restraint Usage) A law requiring some adult occupants of some traffic vehicles to use available restraint systems.  (NHTSA1)

Maneuver Boat: Boat used by the Corps of Engineers in raising and lowering movable wickets of dams on the Ohio River.  (TNDOT1)

Maneuvering: Changing of course, speed, or similar boat handling action during which a high degree of alertness is required or the boat is imperiled because of the operation, i.e. docking, mooring, undocking, etc.  (USCG2)

Maniac: Shop mechanic.  (ATA1)

Manifold Pressure: Absolute pressure as measured at the appropriate point in the induction system and usually expressed in inches of mercury.  (14CFR1)

Manner of Collision: A classification for crashes in which the first harmful event was a collision between two motor vehicles in transport.  (NHTSA3)

Manual Interlocking: An arrangement of signals and signal appliances operated from an interlocking machine and so interconnected by means of mechanical and/or electric locking that their movements must succeed each other in proper sequence, train movements over all routes being governed by signal indication.  (49CFR236)

Manual Restraint System: (See also Mandatory Use Seat Belt Law, Restraint Usage) Occupant restraints that require some action, usually buckling, before they are effective. They include shoulder belt, lap belt, lap and shoulder belt, infant carrier, or child safety seat.  (NHTSA1)

Manufacturer: 1) Any person engaged in the manufacture, construction, or assembly of boats or associated equipment 2) The manufacture or construction of components for boats and associated 3) Equipment to be sold for subsequent assembly or 4) The importation into the United States for sale of boats, associated equipment, or components thereof.  (USCG1)

Manufacturer Identification Code (MIC): Three-character identifier assigned by Headquarters on request to those manufacturers and importers defined under 33 CFR 181.31.  (USCG1)

MAP: Military Airport Plan  (FAA17)

MAP: Missed Approach Point  (FAA4)   (FAA17)

MAR: Managed Arrival Reservoir  (FAA7)

MAR: Minimally Attended Radar  (FAA19)

MARAD: Maritime Administration  (MARAD1)   (MTMC1)

MARDEZ: Maritime Defense Zones  (MARAD4)

Marina: (See also Dock, Pier, Harbor, Wharf) Establishments primarily engaged in operating marinas. These establishments rent boat slips and store boats, and generally perform a range of other services including cleaning and incidental boat repair. They frequently sell food, fuel, and fishing supplies, and may sell boats.  (BOC1)

Marine Cargo Handling: Establishments primarily engaged in activities directly related to marine cargo handling from the time cargo, for or from a vessel, arrives at shipside, dock, pier, terminal, staging area, or in-transit area until cargo loading or unloading operations are completed. Included in this industry are establishments primarily engaged in the transfer of cargo between ship and barges, trucks, trains, pipelines, and wharfs. Cargo handling operations carried on by transportation companies and separately reported are classified here. This industry includes the operation and maintenance of piers, docks, and associated buildings and facilities.  (BOC1)

Marine Pollutant: (See also Hazardous Material) A hazardous material which is listed in Appendix B to CFR 172.101 of this subchapter and, when in a solution or mixture of one or more marine pollutants, is packaged in a concentration which equals or exceeds: 1) Ten percent by weight of the solution or mixture for materials listed in the appendix; or 2) One percent by weight of the solution or mixture for materials that are identified as severe marine pollutants in the appendix.  (49CFR171)

Marine Sanitation Device (MSD): Any equipment for installation on board a vessel which is designed to receive, retrain, treat or discharge sewage and any process to treat such sewage.  (USCG1)

Marine Terminal: A designated area of a port, which includes but not limited to wharves, warehouses, covered and/or open storage spaces, cold storage plants, grain elevators and/or bulk cargo loading and/or unloading structures, landings, and receiving stations, used for the transmission, care, and convenience of cargo and/or passengers in the interchange of same between land and water carriers or between two water carriers.  (MARAD1)

Marine Terminal Operator: Person or entity that operates the various marine terminals at ports, usually under long-term lease agreements with local or state governments or port authorities. The marine terminal operator provides receiving and delivery, and other terminal services for the cargos moving through these facilities.  (MARAD1)

Maritime: Business pertaining to commerce or navigation transacted upon the sea or in seaports in such matters as the court of admiralty has jurisdiction.  (MARAD2)

Maritime Administration (MARAD): The Maritime Administration was established by Reorganization Plan No. 21 of 1950 (5 U.S.C. app.) effective May 24, 1950. The Maritime Act of 1981 (46 U.S.C. 1601) transferred the Maritime Administration to the Department of Transportation, effective August 6, 1981. The Administration administers programs to aid in the development, promotion, and operation of the U.S. Merchant Marine. It is also charged with organizing and directing emergency merchant ship operations. It administers subsidy programs, provides financing guarantees for the construction, reconstruction, and reconditioning of ships; and enters into capital construction fund agreements that grant tax deferrals on moneys to be used for the acquisition, construction, or reconstruction of ships. The Administration constructs or supervises the construction of merchant type ships for the Federal Government, helps industry generate increased business for U.S. ships and conducts programs to develop ports, facilities, and intermodal transport, and to promote domestic shipping. The Administration conducts program and technical studies and administers a War Risk Insurance Program, and under emergency conditions the Maritime Administration charters Government-owned ships to U.S. operators, requisitions or procures ships owned by U.S. citizens, and allocates them to meet defense needs. It maintains a National Defense Reserve Fleet of Government-owned ships, regulates sales to aliens and transfers to foreign registry of ships that are fully or partially owned by U.S. citizens. It also operates the U.S. Merchant Marine Academy, Kings Point.  (OFR1)

Maritime Carrier: Carriers which operate on the open sea, i.e., their operations must include a foreign or international component and may include a domestic component.  (TNDOT1)

Maritime Revenue: Revenue received for operations in international or foreign shipping.  (TNDOT1)

Mark Twain: Colloquial term for 12-foot depth or mark 2 on the lead line.  (TNDOT1)

Marked Channel: Channel marked by buoys.  (TNDOT1)

Marker Beacon: An electronic navigation facility transmitting a 76 mHz vertical fan or boneshaped radiation pattern. Marker beacons are identified by their modulation frequency and keying code, and when received by compatible airborne equipment, indicate to the pilot, both aurally and visually, that he is passing over the facility.  (FAA4)

Marketed Production: Gross withdrawals less gas used for repressuring, quantities vented and flared, and nonhydrocarbon gases removed in treating or processing operations. Includes all quantities of gas used in field and processing operations.  (DOE3)

Marking: A descriptive name, identification number, instructions, cautions, weight, specification, or combinations thereof, required by this subchapter on outer packagings of hazardous materials.  (49CFR171)

MARTA: Metropolitan Atlanta Rapid Transit Authority  (FTA4)

MASPS: Minimum Aviation System Performance Standards  (FAA17)

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

Mass Transportation: Another name for public transportation.  (APTA1)

Mass Transportation Agency: An agency authorized to transport people by bus, rail, or other conveyance, either publicly or privately owned, and providing to the public general or special service (but not including school, charter or sightseeing service) on a regular basis.  (FTA1)

MATCU: Military Air Traffic Coordinating Unit  (MTMC1)

Material Handling: Short-distance movement of goods within a storage area.  (MARAD1)

Material Handling Equipment: Forklift trucks, platform trucks, warehousing industrial cranes, straddle carrier trucks, pallet trucks, platform trucks, warehousing trailers, conveyer systems, and others, used in storage and handling operations.  (MARAD1)

MATES: Mobilization & Training Equipment Site  (MTMC1)

MAWP: Maximum Allowable Working Pressure  (49CFR171)

Maxi-Cube Vehicle: A combination vehicle consisting of a power unit and a trailing unit, both of which are designed to carry cargo. The power unit is a nonarticulated truck with one or more drive axles that carries either a detachable or a permanently attached cargo box. The trailing unit is a trailer or semitrailer with a cargo box so designed that the power unit may be loaded and unloaded through the trailing unit.  (23CFR658)

Maximum Extent Practicable: The limits of available technology and the practical and technical limits on a pipeline operator in planning the response resources required to provide the on-water recovery capability and the shoreline protection and cleanup capability to conduct response activities for a worst case discharge from a pipeline in adverse weather.  (49CFR194)

Maximum High Water Elevation: The highest water level reached during the past 200 years of record keeping.  (TNDOT1)

May Day: (See also Pan Pan) The international radiotelephony distress signal. When repeated three times, it indicates imminent and grave danger and that immediate assistance is requested.  (FAA4)

MBTA: Massachusetts Bay Transportation Authority  (FTA4)

MCA: Minimum Crossing Altitude  (FAA16)   (FAA4)

MCA: Movement Control Agency  (MTMC1)

MCAS: Marine Corps Air Station  (FAA17)

MCC: Maintenance Control Center  (FAA19)

MCDS: Modular Cargo Delivery System  (MARAD4)

MCF: Metroplex Control Facility  (FAA7)   (FAA19)

MCFS: Master Container Freight  (MARAD2)

MCI: Kansas City International Airport  (FAA11)

MCMIS: Motor Carrier Management Information System  (BTS8)   (MM)

MCO: Orlando International Airport  (FAA11)

MCREGIS: Motor Carrier Regulation Information System  (BTS7)

MCS: Monitor and Control Software  (FAA19)

MCSA: Motor Carrier Safety Act of 1984  (FHWA10)

MCSAP: Motor Carrier Safety Assistance Program  (FHWA10)   (NHTSA6)   (RSPA1)

MDA: Minimum Descent Altitude  (14CFR1)   (FAA16)   (FAA17)

MDCRS: Meteorological Data Collection and Reporting System  (FAA17)

MDP: Moving Deformable Barrier  (NHTSA5)

MDT: Harrisburg International  (FAA11)

MDW: Chicago Midway Airport  (FAA11)

MEA: Minimum En Route IFR Altitude  (FAA4)

Mean: (See also Estimate Ratio; Ratio Estimate) The simple arithmetic average for a population; that is, the sum of all the values in a population divided by the size of the population. For this report, population means are estimated by computing the weighted sum of the sample values, then dividing by the sum of the sample weights. The mean is, thus, an aggregate ratio whose denominator is the total number of households or vehicles.  (DOE4)

Means of Transportation: (See also Mode) A mode used for going from one place (origin) to another (destination). Includes private and public modes, as well as walking. For all travel day trips, each change of mode constitutes a separate trip.  (FHWA3)

Measurement Ton: 40 cubic feet.  (MARAD2)

MEBA: Marine Engineers Beneficial Association  (MARAD4)

Median Category: Inclusion of a median within single instance of road.  (DOI3)

Median Included: Median is included within the instance of road.  (DOI3)

Median Not Included: Median is not included because there is no median or median is wide enough to cause separate instances of road.  (DOI3)

Medium Air Traffic Hub: A community enplaning from 0.25 to 0.99 percent of the total enplaned passengers in all services and all operations for all communities within the 50 States, the District of Columbia, and other U.S. areas designated by the Federal Aviation Administration.  (FAA2)   (FAA14)   (FAA15)

Medium or Heavy Trucks: A motor vehicle with a Gross Vehicle Weight Rating (GVWR) greater than 10,000 pounds (buses, motorhomes, and farm and construction equipment other than trucks are excluded).  (NHTSA4)

Medium Regional Carrier Group: Carrier groups with annual operating revenues less than $19,999,999 or that operate only aircraft with 60 seats or less (or 18,000 lbs maximum payload).  (BTS4)   (BTS5)   (BTS6)   (FAA11)

Medium Size Bus: A bus from 29 to 34 feet in length.  (APTA1)

Medium Speed: A speed not exceeding 40 miles per hour.  (49CFR236)

Megawatt: See also Electricity, Gigawatt, Kilowatt.

Megawatt Electric (MWE): One million watts of electric capacity.  (DOE5)

MEM: Memphis International Airport  (FAA11)

MER: Marine Environmental Response  (USCG5)

METAF: Meteorological Terminal Aviation Weather Forecast  (FAA7)

METAR: Meteorological Terminal Aviation Routine Weather Report  (FAA7)

Meteorological Impact Statement: An unscheduled planning forecast describing conditions expected to begin within 4 to 12 hours which may impact the flow of air traffic in a specific Air Route Traffic Control Center's (ARTCC) area.  (FAA4)

Meter Fix/Slot Time: A calculated time to depart the meter fix in order to cross the vertex at the Actual Calculated Landing Time (ACLT). This time reflects descent speed adjustment and any applicable time that must be absorbed prior to crossing the meter fix.  (FAA4)

Metered Data: End-use data obtained through the direct measurement of the total energy consumed for specific uses within the individual household. Individual appliances can be submetered by connecting the recording meters directly to individual appliances.  (DOE5)

Metering: A method of time regulating arrival traffic flow into a terminal area so as not to exceed a predetermined terminal acceptance rate.  (FAA4)

Metering Airports: Airports adapted for metering and for which optimum flight paths are defined. A maximum of 16 airports may be adapted.  (FAA4)

Metering Fix: A fix along an established route from over which aircraft will be metered prior to entering terminal airspace. Normally, this fix should be established at a distance from the airport which will facilitate a profile descent 10,000 feet above airport elevation or above.  (FAA4)

Methanol: A light, volatile alcohol (CH3OH) eligible for motor gasoline blending.  (DOE3)

Methanol: A colorless poisonous liquid with essentially no odor and very little taste. It is the simplest alcohol and boils at 64.7 degrees Celsius. In transportation, methanol is used as a vehicle fuel by itself (M100), or blended with gasoline (M85).  (DOE6)

Metric: Refers to the modernized metric system known as the International System.  (FHWA2)

Metric Ton: A unit of weight equal to 2,204.6 pounds.  (DOE5)

Metropolitan Planning Area: The geographic area in which the metropolitan transportation planning process required by 23 U.S.C. 134 and section 8 of the Federal Transit Act (49 U.S.C. app. 1607) must be carried out.  (23CFR420)

Metropolitan Planning Organization (MPO): The forum for cooperative transportation decisionmaking for a metropolitan planning area.  (23CFR420)

Metropolitan Planning Organization (MPO): Formed in cooperation with the state, develops transportation plans and programs for the metropolitan area. For each urbanized area, a Metropolitan Planning Organization (MPO) must be designated by agreement between the Governor and local units of government representing 75% of the affected population (in the metropolitan area), including the central cities or cities as defined by the Bureau of the Census, or in accordance with procedures established by applicable State or local law (23 U.S.C. 134(b)(1)/Federal Transit Act of 1991 Sec. 8(b)(1)).  (FHWA2)

Metropolitan Railway: Another name for "Heavy Rail."  (APTA1)

Metropolitan Statistical Area (MSA): (See also Central City, Standard Metropolitan Statistical Area) Areas defined by the U.S. Office of Management and Budget. A Metropolitan Statistical Area (MSA) is 1) A county or a group of contiguous counties that contain at least one city of 50,000 inhabitants or more, or 2) An urbanized area of at least 50,000 inhabitants and a total MSA population of at least 100,000 (75,000 in New England). The contiguous counties are included in an MSA if, according to certain criteria, they are essentially metropolitan in character and are socially and economically integrated with the central city. In New England, MSAs consist of towns and cities rather than counties.  (DOE4)   (DOE5)   (FHWA3)

Metropolitan Status: A building classification referring to the location of the building either located within a Metropolitan Statistical Area (MSA) or outside a MSA.  (DOE5)

METW: Military Emergency Travel Warrant  (MTMC1)

Mexican Overdrive: Kicking out of gear going down grade.  (ATA1)

MFP: Multifactor Productivity  (BTS2)

MFT: Meter Fix Time / Slot Time  (FAA4)

MHA: Minimum Holding Altitude  (FAA4)

MIA: Miami International Airport  (FAA11)

MIA: Minimum IFR Altitudes  (FAA4)

Microbridge: A cargo movement in which the water carrier provides a through service between an inland point and the port of load/discharge.  (MARAD2)

Microburst: A small downburst with outbursts of damaging winds extending 2.5 miles or less. In spite of its small horizontal scale, an intense microburst could induce wind speeds as high as 150 knots.  (FAA4)

Microwave Landing System (MLS): An instrument landing system operating in the microwave spectrum which provides lateral and vertical guidance to aircraft having compatible avionics equipment.  (FAA2)   (FAA6)

Microwave Landing System (MLS): A precision instrument approach system operating in the microwave spectrum which normally consists of the following components: 1) Azimuth Station. 2) Elevation Station. 3) Precision Distance Measuring Equipment.  (FAA4)

MID/ASIA: Middle East / Asia Region  (USTTA1)

Midday Period: The period between the end of the A.M. peak and the beginning of the P.M. peak.  (FTA1)

Middle Bar: Bar in middle of river.  (TNDOT1)

Middle Compass Locator (MCL): A compass locator installed at the site of the middle marker of an instrument landing system.  (FAA4)

Middle Marker (MM): (See also Compass Locator, Glideslope, Instrument Landing System, Localizer, Outer Marker) A marker beacon that defines a point along the glideslope of an Instrument Landing System (ILS) normally located at or near the point of decision height (ILS Category I). It is keyed to transmit alternate dots and dashes, with the alternate dots and dashes keyed at the rate of 95 dot/dash combinations per minute on a 1300 Hz tone, which is received aurally and visually by compatible airborne equipment.  (FAA4)

Midgrade Unleaded Gasoline: (See also Fuel, Gasohol, Gasoline, Kerosene) Gasoline having an antiknock index (R+M/2) greater than or equal to 88, or less than or equal to 90, and containing not more than 0.05 grams of lead or 0.005 grams of phosphorus per gallon.  (DOE5)

MIL OPS: Military Operations  (USCG5)

MIL TRA: Military Training  (USCG5)

Mile: See also Kilometer.

Mile: A statute mile (5,280 feet). All mileage computations are based on statute miles.  (BTS5)   (BTS6)

Mile Board: A 12 by 36 inch board mounted horizontally above a shore to aid in navigation and labeled with the river mileage at that point.  (TNDOT1)

Mile Marker: A point on a feature indicating the distance, in miles, measured along the course or path of the feature from an established origin point on the feature.  (DOI3)

Miles In Trail: A specified distance between aircraft, normally, in the same stratum associated with the same destination or route of flight.  (FAA4)

Miles of Road Operated: The single or first main track, measured by the distance between terminals, over which railway transportation service is conducted.  (AAR1)

Miles of Track: The number of tracks per one mile segment of right-of-way. Miles of track are measured without regard to whether or not rail traffic can flow in only one direction on the track. All track is counted, including yard track.  (FTA1)

Miles of Track Operated: (See also Track Mile) Total track mileage consisting of first, second and other main tracks, and of yard tracks and sidings over which railway transportation service is conducted.  (AAR1)

Miles Per Gallon (MPG): A measure of vehicle fuel efficiency. Miles Per Gallon (MPG) represents "Fleet Miles per Gallon". For each subgroup or "table cell", MPG is computed as the ratio of the total number of miles traveled by all vehicles in the subgroup to the total number of gallons consumed. MPGs are assigned to each vehicle using the Environmental Protection Agency (EPA) certification files and adjusted for on-road driving.  (DOE4)   (DOE5)

Miles Per Gallon (MPG) Shortfall: The difference between actual on-road Miles Per Gallon (MPG) and Environmental Protection Agency (EPA) laboratory test MPG. Miles Per Gallon (MPG) shortfall is expressed as gallons per mile ratio (GPMR).  (DOE4)

Military Approach Controls: Military approach control facilities include Army Radar Approach Controls (ARACs), Radar Air Traffic Control Facilities (RATCFs), and Radar Approach Controls (RAPCONs).  (FAA10)

Military Authority Assumes Responsibility For Aircraft Separation: A condition whereby the military services involved assume responsibility for separation between participating military aircraft in the Air Traffic Control (ATC) system. It is used only for required Instrument Flight Rules (IFR) operations which are specified in letters of agreement or other appropriate Force Module (FM) or military documents.  (FAA4)

Military Base: An area owned and operated by the government in which various military activities take place.  (DOI4)

Military Fuel: Kerosene-type jet fuel intended for military use.  (DOE5)

Military Instrument Flight Rules (IFR) Training Route: Routes used by the Department of Defense and associated Reserve and Air Guard units for the purpose of conducting low altitude navigation and tactical training in both Instrument Flight Rules (IFR) and Visual Flight Rules (VFR) weather conditions below 10,000 feet Main Sea Level (MSL) at airspeeds in excess of 250 knots Indicated Airspeed (IAS).  (FAA4)

Military Operations: All classes of military operations.  (FAA13)

Military Operations: Arrivals and departures of aircraft not classified as civil.  (FAA14)

Military Operations Area (MOA): An airspace assignment of defined vertical and lateral dimensions established outside positive control areas to separate/segregate certain military activities from Intermediate Fix (IF) traffic and to identify for Visual Flight Rules (VFR) traffic where these activities are conducted.  (FAA8)

Military Training Route: Airspace of defined vertical and lateral dimensions established for the conduct of military flight training at airspeeds in excess of 250 knots IAS.  (FAA4)

Milk Run: Easy trip.  (ATA1)

Mill Capital: Cost for transportation and equipping a plant for processing ore or other feed materials.  (DOE5)

MILSTAMP: Military Standard Transportation and Movement Procedures  (MTMC1)

MILSTEP: Military Supply and Transportation Evaluation Procedures  (MTMC1)

MILVAN: Military Van  (MTMC1)

Mini Landbridge: An intermodal system for transporting containers by ocean and then by rail or motor to a port previously served as an all-water move.  (MARAD2)

Mini Service: Service station attendants pump vehicle fuel but do not provide other services, such as checking oil and tire pressure or washing windshields.  (DOE5)

Miniature Railway: Small scale railway used for amusement.  (DOI3)

Minibridge: (See also Intermodal, Landbridge) A joint water, rail or truck container move on a single Bill of Lading for a through route from a foreign port to a U.S. port destination through an intermediate U.S. port or the reverse.  (MARAD1)

Minimum Altitude: Instrument Flight Rules (IFR) Minimum altitudes for Instrument Flight Rules (IFR) operations as prescribed in Federal Aviation Regulation (FAR) Part 91. These altitudes are published on aeronautical charts and prescribed in FAR Part 96 for airways and routes, and in FAR Part 97 for standard instrument approach procedures. If no applicable minimum altitude is prescribed in FAR Part 96 or FAR Part 97, the following minimum IFR altitude applies: 1) In designated mountainous areas, 2,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown; 2) Other than mountainous areas, 1,000 feet above the highest obstacle within a horizontal distance of 4 nautical miles from the course to be flown; or 3) As otherwise authorized by the [Federal Aviation Administration (FAA)] Administrator or assigned by Air Traffic Control (ATC).  (FAA4)

Minimum Crossing Altitude: The lowest altitude at certain fixes at which an aircraft must cross when proceeding in the direction of a higher minimum en route Instrument Flight Rules (IFR) altitude (MEA).  (FAA4)

Minimum Descent Altitude: The lowest altitude, expressed in feet above mean sea level, to which descent is authorized on final approach or during circle-to-land maneuvering in execution of a standard instrument approach procedure, where no electronic glide slope is provided.  (14CFR1)

Minimum Descent Altitude (MDA): (See also Height Above Airport) The lowest altitude, expressed in feet above mean sea level, to which descent is authorized on final approach or during circle-to-land maneuvering in execution of a standard instrument approach procedure where no electronic glide slope is provided.  (FAA4)   (FAA8)

Minimum En Route Instrument Flight Rules (IFR) Altitude (MEA): The lowest published altitude between radio fixes which assures acceptable navigational signal coverage and meets obstacle clearance requirements between those fixes. The Minimum En Route Altitude (MEA) prescribed for a federal airway, or segment thereof, area navigation low or high route, or other direct route applies to the entire width of the airway, segment, or route between the radio fixes defining the airway, segment or route.  (FAA4)   (FAA8)

Minimum Fuel: (See also Fuel Remaining) Indicates that an aircraft's fuel supply has reached a state where, upon reaching the destination, it can accept little or no delay. This is not an emergency situation but merely indicates an emergency situation is possible should any undue delay occur.  (FAA4)

Minimum Holding Altitude: The lowest altitude prescribed for a holding pattern which assures navigational signal coverage, communications, and meets obstacle clearance requirements.  (FAA4)

Minimum Instrument Flight Rule (IFR) Altitude (MIA): Minimum altitudes for Instrument Flight Rules (IFR) operations as prescribed in Federal Aviation Regulations (FAR) Part 91.  (FAA8)

Minimum Navigation Performance Specifications: A set of standards which require aircraft to have a minimum navigation performance capability in order to operate in minimum navigation performance specifications (MNPS) designated airspace. In addition, aircraft must be certified by their State of Registry for MNPS operation.  (FAA4)

Minimum Navigation Performance Specifications Airspace (MNPSA): Designated airspace in which minimum navigation performance specifications (MNPS) procedures are applied between MNPS certified and equipped aircraft. Under certain conditions, non-MNPS aircraft can operate in Minimum Performance Specifications Airspace (MNPSA). However, standard oceanic separation minima is provided between the non-MNPS aircraft and other traffic. Currently, the only designated MNPSA is described as follows: 1) Between Flight Level 275 and 400; 2) Between latitudes 27-N. and the North Pole; 3) In the east, the eastern boundaries of the Control Areas (CTA) Santa Maria Oceanic, Shanwick Oceanic, and Reykjavik; 4) In the west, the western boundaries of CTA's Reykjavik and Gander Oceanic and New York Oceanic excluding the area west of 60-W and south of 38-30'N.  (FAA4)

Minimum Obstruction Clearance Altitude: The lowest published altitude in effect between radio fixes on very high frequency (VHF) omnidirectional range (VOR) airways, off-airway routes or route segments which meets obstacle clearance requirements for the entire route segment and which assures acceptable navigational signal coverage only within 25 statute (22 nautical) miles of a VOR.  (FAA4)

Minimum Pool Elevation: The least depth to which a pool is permitted to go and still maintain project channel depth.  (TNDOT1)

Minimum Safe Altitude (MSA): 1) The minimum altitude specified in Federal Aviation Regulation (FAR) Part 91 for various aircraft operations; 2) Altitudes depicted on approach charts which provide at least 1,000 feet of obstacle clearance for emergency use within a specified distance from the navigation facility upon which a procedure is predicated. These altitudes will be identified as Minimum Sector Altitudes or Emergency Safe Altitudes and are established as follows: a) Minimum Sector Altitudes. Altitudes depicted on approach charts which provide at least 1,000 feet of obstacle clearance within a 25-mile radius of the navigation facility upon which the procedure is predicated. Sectors depicted on approach charts must be at least 90 degrees in scope. These altitudes are for emergency use only and do not necessarily assure acceptable navigational signal coverage; b) Emergency Safe Altitudes. Altitudes depicted on approach charts which provide at least 1,000 feet of obstacle clearance in nonmountainous areas and 2,000 feet of obstacle clearance in designated mountainous areas within a 100-mile radius of the navigation facility upon which the procedure is predicated and normally used only in military procedures. These altitudes are identified on published procedures as "Emergency Safe Altitudes."  (FAA4)

Minimum Safe Altitude Warning (MSAW): A function of the Automated Radar Terminal System (ARTS) III computer that aids the controller by alerting him when a tracked Mode C equipped aircraft is below or is predicted by the computer to go below a predetermined minimum safe altitude.  (FAA4)   (FAA8)

Minimum Sector Altitude: The lowest altitude which may be used under emergency conditions which will provide a minimum clearance of 300 m (1,000 feet) above all obstacles located in an area contained within a sector of a circle of 46 km (25 nautical miles) radius centered on a radio aid to navigation.  (FAA4)

Minimum Vectoring Altitude (MVA): The lowest Mean Sea Level (MSL) altitude at which an Instrument Flight Rule (IFR) aircraft will be vectored by a Radar Controller, except as otherwise authorized for radar approaches, departures, and missed approaches.  (FAA8)

Minimums: Weather condition requirements established for a particular operation or type of operation; e.g., Instrument Flight Rules (IFR) takeoff or landing, alternate airport for Instrument Flight Rules (IFR) flight plans, Visual Flight Rules (VFR) flights, etc.  (FAA4)

Mining Danger Area: An area identified as a danger to maritime navigation due to unexploded ordinances.  (DOI3)

Minivan: (See also Automobile, Bus, Car, Motor Vehicle) New type of small van that first appeared with that designation in 1984. Any of the smaller vans built on an automobile-type frame. Earlier models such as the Volkswagen van are now included in this category.  (DOE4)

Minnie: Less than 100 pound shipment.  (ATA1)

Minor Alteration: An alteration other than a major alteration.  (14CFR1)

Minor Arterial: (See also Arterial Highway, Principal Arterial) Streets and highways linking cities and larger towns in rural areas in distributing trips to small geographic areas in urban areas (not penetrating identifiable neighborhoods).  (NHTSA3)

Minor Repair: A repair other than a major repair.  (14CFR1)

Minutes In Trail: A specified interval between aircraft expressed in time. This method would more likely be utilized regardless of altitude.  (FAA4)

MIO: Marine Inspection Operations  (USCG5)

MIP: Maintenance Implementation Plan  (FAA7)

MIP: Mobilization Improvement Program  (MTMC1)

MIRL: Medium Intensity Runway Edge Lights  (FAA16)

MIS: Meteorological Impact Statement  (FAA4)

MISC: Miscellaneous and Other Operations  (USCG5)

Miscellaneous Transport Revenue: Other revenues associated with air transportation performed by air carriers, such as transportation fees collected from those traveling on free or reduced transportation and processing service charges such as lost tickets.  (BTS4)

Missed Approach: (See also Go Around) 1) A maneuver conducted by a pilot when an instrument approach cannot be completed to a landing.The route of flight and altitude are shown on instrument approach procedure charts. A pilot executing a missed approach prior to the Missed Approach Point (MAP) must continue along the final approach to the MAP. The pilot may climb immediately to the altitude specified in the missed approach procedure; 2) A term used by the pilot to inform Air Traffic Control (ATC) that he is executing the missed approach; 3) At locations where ATC radar service is provided, the pilot should conform to radar vectors when provided by ATC in lieu of the published missed approach procedure.  (FAA4)

Missed Approach Point: A point prescribed in each instrument approach procedure at which a missed approach procedure shall be executed if the required visual reference does not exist.  (FAA4)

Missed Approach Procedure: The procedure to be followed if the approach cannot be continued.  (FAA4)

Missed Executed Approach: Instructions issued to a pilot making an instrument approach which means continue inbound to the missed approach point and execute the missed approach procedure as described on the Instrument Approach Procedure Chart or as previously assigned by Air Traffic Control (ATC). The pilot may climb immediately to the altitude specified in the missed approach procedure upon making a missed approach. No turns should be initiated prior to reaching the missed approach point. When conducting an Airport Surveillance Radar (ASR) or Precision Approach Radar (PAR) approach, execute the assigned missed approach procedure immediately upon receiving instructions to "execute missed approach."  (FAA4)

Missile: Sometimes applied to space launch vehicles, but more properly connotes automated weapons of warfare, i.e., a weapon which has an integral system of guidance, as opposed to the unguided rocket.  (AIA1)

MIT: Miles In - Trail  (FAA17)

Miter Gates: Vertical, gates which form the openings of navigation locks; these gates consist of two swinging leaves and close at the center.  (TNDOT1)

Miter Sill: The underwater concrete sill across the openings in the upper and lower lock chamber that the movable lock gates close on. The depth over these cells exceeds project depth and is registered on the several gages within the lock chamber.  (TNDOT1)

Mixed Cargo: Indicates that a vessel carries any combination of grains, government aid, containers, general or bulk cargoes.  (SLSDC1)

Mixed Trains: Mixed trains are passenger-carrying trains consisting of both passenger and freight cars. Freight cars, such as baggage cars, that are equipped with passenger-type braking and suspension systems, are considered to be passenger cars when utilized in passenger service.  (FRA2)

MKE: General Mitchell International Airport  (FAA11)

MLB: Mini Landbridge  (MARAD2)

MLC: Military Load Classification  (BTS8)

MLDI: Meter List Display Interval  (FAA4)

MLS: Microwave Landing System  (FAA2)   (FAA4)   (FAA17)   (FAA6)   (FAA7)

MM: Middle Marker  (FAA4)

MMDOC: Merchant Mariners Documentation  (BTS7)

MMLD: Merchant Mariners Licensing and Documentation  (BTS7)

MMS: Maintenance Management System  (FAA19)

MMT: Million Metric Tons  (BTS2)

MNPS: Minimum Navigation Performance Specifications  (FAA4)   (FAA17)

MNPSA: Minimum Navigation Performance Specifications Airspace  (FAA4)

MNS: Mission Needs Statement  (FAA19)

MOA: Military Operations Area  (FAA4)

MOB: Mobility  (MTMC1)

MOBCON: Mobilization Movement Control  (MTMC1)

MOBERS: Mobilization Equipment Redistribution  (MTMC1)

Mobile Home: A housing unit built on a movable chassis and moved to the site. It may be placed on a permanent or temporary foundation and may contain one room or more. If rooms are added to the structure, it is considered a single-family housing unit. A manufactured house assembled on site is a single-family housing unit, not a mobile home.  (DOE5)

Mobile Home Park: An area maintained for the parking of inhabited mobile homes.  (DOI4)

MOBSCOPE: Mobilization Shipments Configured for Operation Planning and Execution  (MTMC1)

MOBSS: Mobilization Support System  (MTMC1)

MOCA: Minimum Obstruction Clearance Altitude  (FAA4)   (FAA8)

Modal Share: The percentage of total freight moved by a particular type of transportation.  (ATA2)

Modal Split: 1) The proportion of total person trips that uses each of various specified modes of transportation. 2) The process of separating total person trips into the modes of travel used. 3) A term that describes how many people use alternative forms of transportation. It is frequently used to describe the percentage of people who use private automobiles, as opposed to the percentage who user public transportation.  (TRB1)

Mode: See also Means of Transportation.

Mode: Any of the following transportation methods; rail, highway, air, or water.  (49CFR171)

Mode: Transit service operated in a particular format. There are two types: fixed-route and non-fixed route.  (APTA1)

Mode: Transportation planners, analysts, and decisionmakers refer to the means of transportation as a mode.  (BTS2)

Mode: The letter or number assigned to a specific pulse spacing of radio signals transmitted or received by ground interrogator or airborne transponder components of the Air Traffic Control Radar Beacon System (ATCRBS) Mode A (military Mode 3) and Mode C (altitude reporting) are used in air traffic control.  (FAA4)

MODE C: Altitude Reporting Mode of Secondary Radar  (FAA19)

Mode C Intruder Alert: (See also Conflict Alert) A function of certain air traffic control automated systems designed to alert radar controllers to existing or pending situations between a tracked target (known Instrument Flight Rules (IFR) or Visual Flight Rules (VFR) aircraft) and an untracked target (unknown Instrument Flight Rules (IFR) or Visual Flight Rules (VFR) aircraft) that require immediate attention/action.  (FAA4)

Mode S: A secondary surveillance radar and communication system in which each aircraft is assigned a unique address code. Using this unique code, interrogations and other messages can be directed to a particular aircraft, and replies can be unambiguously identified.  (FAA7)

Model Bow: A shaped, pointed bow.  (TNDOT1)

Model Year: The year in which the particular style or design of vehicle was introduced or manufactured.  (DOE4)

Monitor: When used with communication transfer, listen on a specific frequency and stand by for instructions. Under normal circumstances do not establish communications.  (FAA4)

Monkey Line: Small hand line used by a lockman to throw down or bring up lockline.  (TNDOT1)

Monorail: An electrical railway in which a rail car or train of cars is suspended from or straddles a guideway formed by a single beam or rail. Most monorails are either heavy rail or automated guideway systems.  (APTA1)

Monorail: A single rail on which a vehicle or train of cars travels.  (DOI3)

Monorail Vehicles: Guided transit passenger vehicles operating on or suspended from a single rail, beam or tube.  (FTA1)

Mooring: A floating ball, can, or other structure, which is permanently secured to the harbor bottom by means of a heavy chain and anchor system and to which vessels are made fast, but able to swing to the wind and/or current.  (BOC2)

Mooring: The place where a craft may be secured to the ground, wharf, pier, post, or buoy.  (DOI4)

Mooring Cell: (See also Dolphin) A river-front structure generally composed of steel piling or a cluster of wooden piles used for securing barges along the bank at loading facilities.  (TNDOT1)

Moped: (See also Motorcycle, Motor-Driven Cycle) Includes motorized bicycles equipped with a small engine, typically 2 horsepower or less. Minibikes, dirt bikes, and trail bikes are excluded. Note that a motorized bicycle may or may not be licensed for highway use.  (FHWA3)

MOPS: Minimum Operations Performance Standards  (FAA17)

MOST: Mobile Over Snow Transport  (MTMC1)

Most Harmful Event: The event during a crash for a particular vehicle that is judged to have produced the greatest personal injury or property damage.  (NHTSA3)

Most Restrictive State: The mode of an electric or electronic device that is equivalent to a track relay in its deenergized position.  (49CFR236)

Motor Bus: See also Intercity Bus, Motorbus.

Motor Bus: A rubber-tired, self-propelled, manually-steered vehicle with fuel supply carried on board the vehicle.  (APTA1)

Motor Bus: Rubber tired passenger vehicles that operate on roadways. Motor bus service implies fixed routes and schedules.  (FTA2)

Motor Buses, Class A (>35 seats): Rubber tired passenger vehicles powered by diesel, gasoline, battery or alternative fuel engines contained witin the vehicle. Class A motor buses are equipped with more than 35 seats.  (FTA1)

Motor Buses, Class B (25-35 seats): Rubber tired passenger vehicles powered by diesel, gasoline, battery or alternative fuel engines contained witin the vehicle. Class B motor buses are equipped with 25 to 35 seats.  (FTA1)

Motor Buses, Class C (<25 seats): Rubber tired passenger vehicles powered by diesel, gasoline, battery or alternative fuel engines contained witin the vehicle. Class C motor buses are equippedwith less than 25 seats.  (FTA1)

Motor Carrier: 1) A for-hire motor carrier or a private motor carrier of property. The term "motor carrier" includes a motor carrier's agents, officers and representatives as well as employees responsible for hiring, supervising, training, assigning, or dispatching of drivers and employees concerned with the installation, inspection, and maintenance of motor vehicle equipment and/or accessories. 2) An employer firm that is primarily engaged in providing commercial motor freight or long distance trucking or transfer services.  (49CFR390)

Motor Carrier of Passengers: A common, contract, or private carrier using a bus to provide commercial transportation of passengers.  (23CFR658)

Motor Freight Transportation Warehousing and Stockyards: Includes establishments that provide local or long-distance trucking or transfer services, warehousing and storage of farm products, furniture or other household goods, and commercial goods of a general nature. The operation of terminal facilities for handling freight, with or without maintenance facilities is also included. Stockyards, establishments that provide holding pens for livestock in transit, are included in this major group. These stock yards do not sell or auction livestock.  (BEA1)

Motor Gasoline: See also Fuel, Gasohol.

Motor Gasoline: A complex mixture of relatively volatile hydrocarbons, with or without small quantities of additives, obtained by blending appropriate refinery streams to form a fuel suitable for use in spark ignition engines. Motor gasoline includes both leaded and unleaded grades of finished motor gasoline, blending components, and gasohol.  (DOE3)   (DOE5)

Motor Home: Includes self-powered recreational vehicles (RV) that are operated as a unit without being towed by another vehicle (e.g., a Winnebago motor home).  (FHWA3)

Motor Vehicle: See also Automobile, Bus, Car, Minivan, Semitrailer, Taxi, Tractor (or Truck Tractor), Tractor-Semitrailer, Truck, Van, Vehicle.

Motor Vehicle: Any mechanically or electrically powered device not operated on rails, upon which or by which any person or property may be transported upon a land highway. The load on a motor vehicle or trailer attached to it is considered part of the vehicle.  (NSC1)

Motor Vehicle: A vehicle, machine, tractor, trailer, or semitrailer, or any combination thereof, propelled or drawn by mechanical power and used upon the highways in the transportation of passengers or property. It does not include a vehicle, locomotive, or car operated exclusively on a rail or rails, or a trolley bus operated by electric power derived from a fixed overhead wire, furnishing local passenger transportation similar to street-railway service.  (49CFR171)   (49CFR383)   (49CFR390)

Motor Vehicle Accident: An unstabilized situation that includes at least one harmful event (injury or property damage) involving a motor vehicle in transport (in motion, in readiness for motion or on a roadway, but not parked in a designated parking area) that does not result from discharge of a firearm or explosive device and does not directly result from a cataclysm.  (NSC1)

Motor Vehicle Chassis: The basic operative motor vehicle, including engine, frame, and other essential structures and mechanical parts, but excluding body and all accessories and auxiliary equipment.  (GSA2)

Motor Vehicle In Transport: A motor vehicle in motion on the trafficway or any other motor vehicle on the roadway, including stalled, disabled, or abandoned vehicles.  (NHTSA3)

Motor Vehicle Traffic Accident: An accident involving a motor vehicle in use within the right-of-way or other boundaries of a trafficway open for the use of the public.  (FHWA1)   (NSC1)

Motor Vessel: Any vessel equipped with propulsion machinery (other than steam) more than sixty-five feet long.  (USCG2)

Motor-Driven Cycle: (See also Moped, Motorcycle) A motorcycle with a motor that produces 5 brake horsepower or less.  (49CFR571)

Motorboat: See also Boat, General Cargo Ship, Towboat.

Motorboat: Any vessel equipped with propulsion machinery, not more than sixty-five feet in length.  (USCG2)

Motorbus: See also Intercity Bus, Motor Bus, School and Other Nonrevenue Bus, Transit Bus.

Motorbus: Rubber tired, self-propelled, manually steered bus with fuel supply on board the vehicle. Motor bus types include intercity, school, and transit.  (DOE6)

Motorbus: Rubber tired passenger vehicles which operate on roadways. Motorbus service implies fixed routes and schedules.  (FTA1)

Motorcycle: See also Moped, Motor-Driven Cycle.

Motorcycle: All two or three wheeled motorized vehicles. Typical vehicles in this category have saddle type seats and are steered by handle bars rather than a wheel. This category includes motorcycles, motor scooters, mopeds, motor powered bicycles, and three wheeled motorcycles.  (FHWA2)

Motorcycle: A two- or three-wheeled motor vehicle designed to transport one or two people, including motorscooters, minibikes, and mopeds.  (NHTSA3)

Motorized Vehicle: Includes all vehicles that are licensed for highway driving. Specifically excluded are snow mobiles and minibikes.  (FHWA3)

Mouth: The exit or point of discharge of a stream into another stream, lake, or sea.  (DOI4)

Movable Bridge: That section of a structure bridging a navigable waterway so designed that it may be displaced to permit passage of traffic on the waterway.  (49CFR236)

Movable Bridge Locking: The rail locks, bridge locks, bolt locks, circuit controllers, and electric locks used in providing interlocking protection at a movable bridge.  (49CFR236)

Movable Dam: A dam that is predominantly constructed of a series of wickets which may be raised or lowered as water stages dictate for passing water through the dam. These wickets may all be lowered at the bed of the river and vessels may pass over the dam during periods of high water. The dam and/or river is then said to be "open".  (TNDOT1)

Movement Area: 1) The runways, taxiways, and other areas of an airport/heliport which are utilized for taxiing/hover taxiing, air taxiing, takeoff, and landing of aircraft, exclusive of loading ramps and parking areas. At those airports/heliports with a tower, specific approval for entry onto the movement area must be obtained from ATC. 2) That part of an aerodrome to be used for the takeoff, landing and taxiing of aircraft, consisting of the maneuvering area and the apron(s).  (FAA4)

Moving Target Indicator: An electronic device which will permit radar scope presentation only from targets which are in motion. A partial remedy for ground clutter.  (FAA4)

MPG: Miles Per Gallon  (BTS2)   (DOE4)   (NHTSA5)

MPH: Miles Per Hour  (BTS8)

MPO: Metropolitan Planning Organization  (FHWA8)   (MTMC1)

MPRS: Marine Pollution Retrieval System  (BTS8)

MPRSA: Marine Protection Research and Sanctuaries Act  (FHWA12)

MRA: Minimum Reception Altitude  (FAA4)

MRO: Medical Review Officer  (FHWA10)

MRS: Mobility Requirements Study  (MTMC1)

MRU: Movement Release Unit  (MTMC1)

MSA: Marine Science Activities  (USCG5)

MSA: Metropolitan Statistical Area  (BTS8)   (FHWA3)

MSA: Minimum Safe Altitude  (FAA4)   (FAA8)

MSAW: Minimum Safe Altitude Warning  (FAA4)   (FAA19)

MSB: Maritime Subsidy Board  (MARAD4)

MSC: Marine Safety Council  (USCG1)

MSC: Military Sealift Command  (MARAD4)   (MTMC1)

MSD: Marine Sanitation Device  (USCG1)

MSIS: Marine Safety Information System  (RSPA1)

MSL: Mean Sea Level  (FAA2)   (FAA6)

MSMS: Marine Safety Management System  (BTS7)

MSN: Dane County Regional - Truax Field  (FAA11)

MSO: Marine Safety Office  (USCG5)

MSP: Marine Security Program  (FHWA12)

MSP: Minneapolis - St Paul International Airport  (FAA11)

MSPS: Mobilization Station Planning System  (MTMC1)

MSR: Main Supply Route  (MTMC1)

MSS: Motor Surveillance Service  (MTMC1)

MSTAT: Marine Safety Training and Assistance Team  (RSPA1)

MSW: Maximum Shipping Weight  (MTMC1)

MSY: New Orleans International Airport / Moisant Field  (FAA11)

MT: Metric Ton  (MARAD2)

MTA: Metropolitan Transportation Authority (New York)  (FTA4)

MTB: Materials Transportation Bureau  (OFR1)

MTBE: Methyl Tertiary Butyl Ether  (DOE6)

MTI: Moving Target Indicator  (FAA4)

MTIS: Multimodal Traveler Information Systems  (FTA4)

MTMC: Military Traffic Management Command  (MARAD4)

MTMCTEA: Military Traffic Management Command Transportation Engineering Agency  (MTMC1)

MTMCTTC: Military Traffic Management Command Transportation Terminal Command, Europe  (MTMC1)

MTN: Multilateral Trade Negotiations  (AIA1)

MTR: Military Training Routes  (FAA4)

MTS: Mobil - Trac System  (MTMC1)

Mu Locomotive: A multiple operated electric locomotive described in 49 CFR 229.4 paragraph (i)(2) or (3).  (49CFR229)

Mule: Small tractor used in warehouse to pull two axle dollies, also yard tractor.  (ATA1)

Mule Train: The maneuver of towboats in ice-choked channels whereby the tow is strung out single file, the barges fitted with loose couplings or lashings, and the tow pulled behind the towboat. Also known as string out.  (TNDOT1)

Multi Stop Body: Fully enclosed truck body with driver's compartment designed for quick, easy entrance and exit.  (ATA1)

Multi-Trailer Five or Less Axle Truck: All vehicles with five or less axles consisting of three or more units, one of which is a tractor or straight truck power unit.  (FHWA2)

Multi-Trailer Seven or More Axle Truck: All vehicles with seven or more axles consisting of three or more units, one of which is a tractor or straight truck power.  (FHWA2)

Multi-Trailer Six Axle Truck: All six axle vehicles consisting of three or more units, one of which is a tractor or straight truck power-unit.  (FHWA2)

Multicom: A mobile service not open to public correspondence used to provide communications essential to conduct the activities being performed by or directed from private aircraft.  (FAA4)

Multimodal Transportation: (See also Intermodal) Often used as a synonym for intermodalism. Congress and others frequently use the term intermodalism in its broadest interpretation as a synonym for multimodal transportation. Most precisely, multimodal transportation covers all modes without necessarily including a holistic or integrated approach.  (BTS2)

Multiple Runway: The utilization of a dedicated arrival runway(s) for departures and a dedicated departure runway(s) for arrivals when feasible to reduce delays and enhance capacity.  (FAA4)

Multipurpose Passenger Vehicle: A motor vehicle with motive power, except a trailer, designed to carry 10 persons or less which is constructed either on a truck chassis or with special features for occasional off-road operation.  (49CFR571)

MUTCD: Manual On Uniform Traffic Control Devices  (FRA4)   (MOCD)

MV: Motor Vehicle  (FRA4)

MVA: Minimum Vectoring Altitude  (FAA4)

MWE: Megawatt Electric  (DOE7)

MWP: Meteorologist Weather Processor  (FAA17)   (FAA19)

MY: Model Year  (NHTSA5)