U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
| 3S2 | 3-axle tractor with a 2-axle semi-trailer |
| AADT | Annual Average Daily Traffic |
| AADTT | Annual Average Daily Truck Traffic |
| AASHTO | American Association of State Highway and Transportation Officials |
| AAWDT | Annual Average Weekday Traffic |
| ADMS | Archived Data Management System |
| ADT | Average Daily Traffic |
| ADUS | Archived Data User Service |
| APTS | Advanced Public Transportation Systems |
| ARTS | Advanced Rural Transportation Systems |
| ASTM | American Society for Testing and Materials |
| ATIS | Advanced Traveler Information System |
| ATS | Average Tandem Spacing |
| ATMS | Advanced Traffic Management System |
| ATR | Automated Traffic Recorder |
| AVC | Automatic Vehicle Classification |
| AVDT | Annual Vehicle Distance Traveled |
| BMS | Bridge Management System |
| CAAA | Clean Air Act Amendments (1990) |
| CCS | Continuous Count Station |
| CFR | Code of Federal Regulations |
| CMS | Congestion Management System |
| CVC | Continuous Vehicle Classifier |
| CVO | Commercial Vehicle Operations |
| DOT | Department of Transportation |
| DOW | Day of Week |
| DVDT | Daily Vehicle Distance Traveled |
| EAL | Equivalent Axle Loading |
| EPA | Environmental Protection Agency |
| ESAL | Equivalent Single Axle Loading |
| FHWA | Federal Highway Administration |
| FIPS | Federal Information Processing Standards |
| GIS | Geographic Information System |
| GPS | Global Positioning System |
| HOD | Hour of Day |
| HPMS | Highway Performance Monitoring System |
| IRI | International Roughness Index |
| ISTEA | Intermodal Surface Transportation Efficiency Act (1991) |
| ITS | Intelligent Transportation System |
| KIPS | Kilopounds (thousands of pounds) |
| LRS | Linear Referencing System |
| LTBP | Long Term Bridge Performance |
| LTPP | Long Term Pavement Performance |
| LTTP | Long-Term Transportation Plan |
| MADT | Monthly Average Daily Traffic |
| MADTT | Monthly Average Daily Truck Traffic |
| MAF | Monthly Adjustment Factor |
| MAP-21 | Moving Ahead for Progress in the 21st Century Act (2012) |
| MAWDT | Monthly Average Weekday Daily Traffic |
| MAWDTT | Monthly Average Weekday Daily Truck Traffic |
| MAWET | Monthly Average Weekend Daily Traffic |
| MOY | Month of Year |
| MPO | Metropolitan Planning Organization |
| NEPA | National Environmental Policy Act |
| NHPN | National Highway Planning Network |
| NHS | National Highway System |
| NIT | National Institute of Technology |
| NPS | National Park Service |
| OFE | Other Freeways and Expressways |
| OPA | Other Principal Arterial |
| PAS | Principal Arterial System |
| PHF | Peak Hour Factor |
| PMS | Pavement Management System |
| PSR | Present Serviceability Rating |
| PTR | Portable Traffic Recorder |
| RF | Radio Frequency |
| SADT | Seasonal Average Daily Traffic |
| SAWA | Steering Axle Weight Average |
| SHRP | Strategic Highway Research Program |
| TEA21 | Transportation Equity Act for the 21st Century |
| TMAS | Travel Monitoring Analysis System |
| TMG | Traffic Monitoring Guide |
| TVT | Travel Volume Trends |
| TWS | Truck Weight Study |
| UPACS | User Profile and Access Control System |
| VDT | Vehicle Distance Traveled |
| VMT | Vehicle Miles Traveled |
| VTRIS | Vehicle Travel Information System |
| WIM | Weigh-in-Motion |
