| 4Ts | Tolling, Transit, Telecommuting, and Technology |
| APC | Automatic passenger counter |
| ASTM | American Society for Testing Materials |
| ATM | Active traffic management |
| AVL | Automatic vehicle location |
| AVO | Average vehicle occupancy |
| BFI | Boeing Field/King County International Airport |
| CAD | Computer aided dispatch |
| CBA | Cost and benefit analysis |
| CRD | Congestion Reduction Demonstration |
| CSC | Customer Service Center |
| CTR | Commute Trip Reduction |
| CTS | Center for Transportation Studies |
| CUTR | Center for Urban Transportation Research |
| CVISN | Commercial Vehicle Information Systems and Networks |
| CVO | Commercial vehicle operator |
| DOE | U.S. Department of Energy |
| DVAS | Digital Video Audit System |
| EJ | Environmental justice |
| FHWA | Federal Highway Administration |
| FMAS | Facility Management and Administration System |
| FTA | Federal Transit Administration |
| GTEC | Growth and Transportation Efficiency Center |
| HOT | High-occupancy tolling |
| HOV | High-occupancy vehicle |
| HOV 2+ | High-occupancy vehicle containing two or more travelers |
| HOV 3+ | High-occupancy vehicle containing three or more travelers |
| IRT | Incident Response Teams |
| ITS | Intelligent transportation systems |
| ITS JPO | Intelligent Transportation Systems Joint Program Office |
| LWC | Lake Washington Corridor |
| MOE | Measure of effectiveness |
| MOVES | Motor Vehicle Emission Simulator |
| NEF | National Evaluation Framework |
| P&R | Park-and-ride |
| PMT | Person-miles traveled |
| PSRC | Puget Sound Regional Council |
| PT | Person throughput |
| RFP | Request for Proposal |
| RITA | Research and Innovative Technology Administration |
| RTCS | Roadside Toll Collection System |
| SOV | Single-occupant vehicle |
| SPT | Service Planning Tool |
| TCI | Transit Competitiveness Index |
| TCS | Toll Collection System |
| TDM | Travel demand management |
| TMC | Traffic Management Center |
| TRIPS | Transportation Information Planning Support |
| TSMC | Traffic Systems Management Center |
| TTI | Texas Transportation Institute |
| UPA | Urban Partnership Agreement |
| U.S. DOT | U.S. Department of Transportation |
| VMT | Vehicle miles traveled |
| VT | Vehicle trips |
| WITS | WSDOT Incident Response Tracking System |
| WSDOT | Washington State Department of Transportation |
