WSDOT is recognized for its commitment to accurate and quality reporting on congestion. Since 1988, the department has been collecting, analyzing, and reporting on congestion to help the public and officials better understand how congestion is evolving and what mitigation strategies are effective for improving commutes. In 2007, the Legislature amended RCW 47.01.012 to create six transportation policy goals , including Mobility – Congestion Relief. WSDOT has adapted and expanded its congestion reporting to include mobility and congestion relief programs in all of its strategic and performance-based reporting, including the Gray Notebook.
The Corridor Capacity Report
WSDOT's Annual Corridor Capacity Report (previously the Congestion Report) is the agency's comprehensive annual multimodal analysis of state highway system performance.
The Corridor Capacity Report informs the Legislature, stakeholders, education and research institutions, the media, communities and the public about the state of congestion and transportation capacity in Washington State. The detailed analysis in the report shows where and how much congestion occurs, and whether it has grown on state highways. The report focuses on the most traveled commute corridors around the state.
In addition to the Corridor Capacity Report, a data Appendix (pdf 9.8 mb) covers detailed performance measures in the form of tables, additional graphs, and information on all commute routes.
WSDOT's Handbook for Corridor Capacity Evaluation (pdf 4.9 mb) and Addendum (950 kb) are comprehensive methodology tools for implementing system performance measurement as part of the WSDOT's accountability initiatives and the federal Moving Ahead for Progress in the 21st Century (MAP-21) requirements.
Semi-Annual Travel Trends Report
In 2008, WSDOT published its first semi-annual travel trends report as a result of the rapidly changing economy experienced nationally, as well as in Washington state. WSDOT has continued to produce these reports to provide an interim update on travel time trends in the central Puget Sound region as the Congestion Working Group manages to produce the comprehensive WSDOT Annual Congestion Report.
The Gray Notebook includes quarterly and annual updates on key mobility programs that help to mitigate congestion and provide alternate commute options: the Incident Response Program , Washington State Ferries (WSF), and Amtrak Cascades . For WSF and Amtrak Cascades , these reports track key performance metrics such as ridership, on-time performance, and service reliability, and for the Incident Response program, the number of incidents cleared statewide and average clearance times. The annual Commute Options report tracks programs and trends like the percentage of Washington drivers who commute alone and alternative commute programs such as state-supported vanpools. See the Gray Notebook Subject Index for historical documents.
Recent Mobility Updates:
Practical Design and Least Cost Planning offer solutions
WSDOT uses least cost planning and practical design strategies to fight congestion while enabling more flexible and sustainable transportation investment decisions. As part of its regular congestion reporting, WSDOT shows how its programs and projects use these and other strategies to help fight congestion. Please visit the Practical Solutions website for more information.
In addition, WSDOT uses its real-time data collection tools to help commuters plan their trips in ways that avoid or reduce additional congestion:
WSDOT's Congestion Flow Map and Traffic Cameras : This page shows the level of congestion on state highways and live traffic images.
Current Seattle Area Travel Times : Using real-time data, this page provides users an estimate of the expected travel times between locations on select highways
Plan Your Commute: 95% Reliable Travel Times : Based on historical data, users can get a reliable (19 out of 20 trips) estimate of the travel time between selected locations.