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N/A: Not Applicable (FAA20)

N2O: Nitrous Oxide (BTS10)

NAA: National Airspace Analysis (FAA7)

NAA: Non-Attainment Area (FTA5)

NAAQNA: National Ambient Air Quality Nonattainment Area (FHWA19)

NAAQS: National Ambient Air Quality Standards (FHWA8)

NAC: Noise Abatement Criteria (FHWA18)

NACA: National Advisory Committee On Aeronautics (OST3)

NACE: National Association of County Engineers (FHWA18)

NACG: National Aeronautical Charting Group (FAA20)

NACo: National Association of Counties (FHWA18)

NADA: NADIN Concentrator (FAA20)

NADA: National Automotive Dealers Association (GSA2)

NADIN: National Airspace Data Interchange Network (FAA20)

NADO: National Association of Development Organizations (FHWA18)

NADS: National Advanced Driver Simulator (NHTSA5)

NADSW: NADIN Switches (FAA20)

NAE: National Academy of Engineering (FHWA19)

NAFTA: North American Free Trade Agreement (BTS2)

NAGHSR: National Association of Governor's Highway Safety Representatives (NHTSA6)

NAGIS: National Airport Grant Information System (FAA7)

NAICS: North American Industry Classification System (BTS2)

NAILS: National Airspace Integrated Logistics Support (FAA20)

NAIMS: National Airspace Information System (BTS8)

NAM: North American Region (USTTA1)


NANI: M Nationwide Airport Noise Impact Model (BTS11)

NAP: Needs Assessment Program (FAA20)

NAPA: National Asphalt Pavement Association (FHWA20)

NAPCOM: National Pavement Cost Model (FHWA19)

Naphtha: A generic term applied to a petroleum fraction with an approximate boiling range between 122 and 400 degrees Fahrenheit. (DOE3)

Naphtha-Type Jet Fuel: A fuel in the heavy naphtha boiling range with an average gravity of 52.8 degrees American Petroleum Institute (API) and 20 to 90 percent distillation temperatures of 290 degrees to 470 degrees Fahrenheit, meeting Military Specification MIL-T-5624L (Grade JP-4). JP-4 is used for turbojet and turboprop aircraft engines, primarily by the military. Excludes ram-jet and petroleum rocket fuels. (DOE5) (DOE6)

NAPM: National Associate Program Manager (FAA20)

NAPRS: National Airspace Performance Reporting System (FAA3)

NAR: National Airspace Review 66 (FAA20)

NARA: National Archives and Records Administration (FHWA18)

NARACS: National Radio Communications System (FAA20)

NARC: National Association of Regional Councils (FHWA18)

NARP: National Aviation Research Plan (FAA20)

Narrow Channel: Channel with very little room to spare. (TNDOT1)

Narrow Railway Gauge: Distance between the rails of a track less than 4 ft 8.5 inches. (DOI3)

NAS: National Airspace System (DOT1)

NAS: Naval Air Station (FAA17)

NAS: National Academy of Sciences (FHWA19)

NASA: National Aeronautics and Space Administration (BTS10)

NASBLA: National Association of State Boating Law Administrators (USCG1)

NASDAC: National Aviation Safety Data Analysis Center (FAA19)

NASDC: National Aviation Safety Data (FAA20)

NASE: NAS Adaptation Services Environment (FAA20)

NASIP: National Aviation Safety Inspection Program (RSPA1)

NASMAP: NAS Management Automation Program (FAA19)

NASP: National Airspace System Plan (FAA17) (FAA8)

NASPAC: National Airspace System Performance Analysis Capability (FAA20)

NASPALS: Nas Precision Approach and Landing System (FAA17)

NASR: National Airspace System Resources (FAA20)

NASS: National Accident Sampling System (NHTSA5) (NHTSA2)

NASS: National Automotive Sampling System (NHTSA7)

NASTEP: National Airspace System Technical Evaluation Program (FAA20)

NAT: North Atlantic Region (USTTA1)

NATCA: National Air Traffic Controllers Association (DOT1)

NATCO: National Communications Switching Center (FAA20)

Nation's Freight Bill: The amount spent annually on freight transportation by the nation's shippers; also represents the total revenue of all carriers operating in the nation. (ATA2)

National Airspace System: The common network of U.S. airspace; air navigation facilities, equipment, and services; airports or landing areas; aeronautical charts, information, and services; rules, regulations, and procedures; technical information, manpower, and material. Included are system components shared jointly with the military. (FAA4) (FAA8)

National Airspace System Stage A: The en route Air Traffic Control (ATC) system's radar, computers and computer programs, controller plan view displays (Plan View Displays (PVD)/Radar Scopes), input/output devices, and the related communications equipment which are integrated to form the heart of the automated Instrument Flight Rules (IFR) air traffic control system This equipment performs Flight Data Processing (FDP) and Radar Data Processing (RDP). It interfaces with automated terminal system and is used in the control of en route Instrument Flight Rules (IFR) aircraft. (FAA4)

National Ambient Air Quality Standards : Federal standards that set allowable concentrations and exposure limits for various pollutants. The EPA developed the standards in response to a requirement of the CAA. Air quality standards have been established for the following six criteria pollutants: ozone (or smog), carbon monoxide, particulate matter, nitrogen dioxide, lead, and sulfur dioxide. (FHWA21)

National Beacon Code Allocation Plan Airspace: Airspace over United States territory located within the North American continent between Canada and Mexico, including adjacent territorial waters outward to about boundaries of oceanic control areas (CTA)/Flight Information Regions (FIR). (FAA4)

National Boating Safety Advisory Council: A 21 member council, equally represented by industry, the public, and State Boating Law Administrators, with expertise, knowledge and experience in boating safety. The Council acts in an advisory or consulting capacity to the Commandant. (USCG1)

National Bridge Inspection Standards: Federal regulations establishing requirements for inspection procedures, frequency of inspections, qualifications of personnel, inspection reports, and preparation and maintenance of a State bridge inventory. (FHWA6)

National Bridge Inventory: The aggregation of structure inventory and appraisal data collected to fulfill the requirements of the National Bridge Inspection Standards that each State shall prepare and maintain an inventory of all bridges subject to the National Bridge Inspection Standards. (FHWA6)

National Carrier Group: Air carrier groups with annual operating revenues between $100,000,000 and $1,000,000,000. (BTS4) (BTS5) (BTS6) (FAA11)

National Cooperative Highway Research Program: The cooperative research, development, and technology transfer (RD&T) program directed toward solving problems of national or regional significance identified by States and the FHWA, and administered by the Transportation Research Board, National Academy of Sciences. (23CFR420)

National Cooperative Transit Research and Development Program: A program established under Section 6a) of the Urban Mass Transportation Act of 1964, as amended, to provide a mechanism by which the principal client groups of the Urban Mass Transportation Administration can join cooperatively in an attempt to resolve near-term public transportation problems through applied research, development, testing, and evaluation. NCTRP is administered by the Transportation Research Board. (TRB1)

National Environmental Policy Act of 1969: Established a national environmental policy requiring that any project using federal funding or requiring federal approval, including transportation projects, examine the effects of proposed and alternative choices on the environment before a federal decision is made. (FHWA21)

National Flight Data Center: A facility in Washington DC, established by Federal Aviation Administration (FAA) to operate a central aeronautical information service for the collection, validation, and dissemination of aeronautical data in support of the activities of government, industry, and the aviation community. The information is published in the National Flight Data Digest. (FAA4)

National Flight Data Digest: A daily (except weekends and Federal holidays) publication of flight information appropriate to aeronautical charts, aeronautical publications, Notices to Airmen, or other media serving the purpose of providing operational flight data essential to safe and efficient aircraft operations. (FAA4)

National Highway System: This system of highways designated and approved in accordance with the provisions of 23 United States Code 103b Federal-aid systems. (BTS12)

National Highway Traffic Safety Administration: The Administration was established by the Highway Safety Act of 1970 (23 U.S.C. 401 note). The Administration was established to carry out a congressional mandate to reduce the mounting number of deaths, injuries, and economic losses resulting from motor vehicle crashes on the Nation's highways and to provide motor vehicle damage susceptibility and ease of repair information, motor vehicle inspection demonstrations and protection of purchasers of motor vehicles having altered odometers, and to provide average standards for greater vehicle mileage per gallon of fuel for vehicles under 10,000 pounds (gross vehicle weight). (OFR1)

National Historic Trail: A historic or prehistoric route of travel of significance to the entire Nation. It must meet three criteria listed in Section 5(b)(11) of the National Trails System Act, and be established by Act of Congress. 16 U.S.C. 1241-51. (FHWA21)

National Income: The aggregate earnings of labor and property which arise in the current production of goods and services by the nation's economy. (DOE6)

National Inland Waterways Transport: Inland waterways transport between two places (a place of IWT loading/embarkment and a place of unloading/disembarking) located in the same country irrespective of the country in which the IWT vessel is registered. It may involve transit through a second country. (TNDOT1)

National Inland Waterways Transport Vessel: Inland Waterways Transport (IWT) vessel which is registered at a given date in the reporting country. (TNDOT1)

National ITS Architecture: A systems framework to guide the planning and deployment of ITS infrastructure. The national ITS architecture is a blueprint for the coordinated development of ITS technologies in the U.S. It is unlikely that any single metropolitan area or state would plan to implement the entire national ITS architecture. (FHWA21)

National Scenic Byways Program: Designates roads that have outstanding scenic, historic, cultural, natural, recreational, and archaeological qualities as All-American Roads or National Scenic Byways, and provides grants for scenic byway projects. 23 U.S.C. 162 (FHWA21)

National Scenic Trail: A continuous, primarily nonmotorized route of outstanding recreation opportunity, established by Act of Congress. 16 U.S.C. 1241-51. (FHWA21)

National Search and Rescue Plan: An interagency agreement which provides for the effective utilization of all available facilities in all types of search and rescue missions. (FAA4)

National Trails System: The network of scenic, historic, and recreation trails created by the National Trails System Act of 1968. These trails provide for outdoor recreation needs, promote the enjoyment, appreciation, and preservation of open-air, outdoor areas and historic resources, and encourage public access and citizen involvement. 16 U.S.C. 1241-51. (FHWA21)

National Transit Database: (Formerly Section 15) A reporting system, by uniform categories, to accumulate mass transportation financial and operating information and a uniform system of accounts and records. The reporting and uniform systems shall contain appropriate information to help any level of government make a public sector investment decision. The Secretary [of Transportation] may request and receive appropriate information from any source. (FTA1)

National Transportation System: An intermodal system consisting of all forms of transportation in a unified, interconnected manner to reduce energy consumption and air pollution while promoting economic development and supporting the Nation's preeminent position in international commerce. The NTS includes the National Highway System (NHS), public transportation and access to ports and airports. (APTA1)

Nationals (Air): Air carrier groups with annual operating revenues between $100 million and $1 billion. (BTS11)

Nationwide Personal Transportation Survey: A periodic national survey that provides comprehensive information on travel by the U.S. population, along with related socioeconomic characteristics of the tripmaker. The Nationwide Personal Transportation Survey (NPTS) is designed to allow an analysis of travel by characteristics of the trip (e.g., length, purpose, mode), the tripmaker (e.g., age, sex, household income) and the vehicle used (e.g., model year, vehicle type, make and model). NPTS surveys were conducted in 1969, 1977 and 1983 by the Bureau of Census (BOC) for the Department of Transportation (DOT). The 1990 NPTS was sponsored by a group of DOT agencies, specifically the Federal Highway Administration (FHWA), Federal Railroad Administration (FRA), National Highway Traffic Safety Administration (NHTSA), Office of the Secretary (OST), and the Federal Transit Administration (FTA). The survey was conducted for DOT by Research Triangle Institute. Information was collected on all trips taken by each household member age 5 and older during a designated 24-hour period, known as a "travel day," and on trips of 75 miles or more taken during the preceding 14-day period, known as the "travel period." The trip information was expanded to annual estimates of trips and travel. The survey encompassed trips on all modes of transportation for all trip purposes and all lengths. (FHWA3)

Native American Local Technical Assistance Programs: Primarily responsible for transportation related technology transfer to Native Americans through Tribal Technical Assistance Program (TTAP) Centers. (FHWA21)

NATMEC: North American Travel Monitoring Exhibition and Conference (FHWA20)

NATO: North American Treat Organization (AIA1)

NATS: National Air Traffic Service (FAA20)

NATS: North American Trucking Survey (AAR) (FHWA19)

Natural Gas: A naturally occurring mixture of hydrocarbon and nonhydrocarbon gases found in porous geologic formations beneath the Earth's surface, often in association with petroleum. The principal constituent is methane. (BTS11)

Natural Gas Distribution Pipeline: Smaller than transmission pipelines and maintained by companies that distribute natural gas locally (intrastate). Distribution pipeline systems are analogous to networks of lesser roads and residential streets that people travel after getting off the freeway. (BTS13)

Natural Gas Marketed Production: Gross withdrawals of natural gas from production reservoirs, less gas used for reservoir repressuring; nonhydrocarbon gases removed in treating and processing operations; and quantities vented and flared. (DOE3)

Natural Gas Plant Liquids: Liquids recovered from natural gas in processing plants or field facilities, or extracted by fractionators. They include ethane, propane, normal butane, isobutane, pentanes plus, and other products, such as finished motor gasoline, finished aviation gasoline, special naphthas, kerosene, and distillate fuel oil produced at natural gas processing plants. (BTS11)

Natural Gas Policy Act of 1978: Section 311 Construction, allows an interstate pipeline company to transport gas "on behalf of" any intrastate pipeline or local distribution company. Pipeline companies may expand or construct facilities used solely to enable this transportation service, subject to certain conditions and reporting requirements. (DOE1)


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