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Congestion reporting at WSDOT

The Multimodal Corridor Capacity Report

WSDOT's annual multimodal Corridor Capacity Report (pdf 11.2 mb) (previously the Congestion Report) is the agency's comprehensive annual multimodal analysis of state highway system performance.

Reports by Year

(PDF Format)

2016 (pdf 11.2 mb)

2011 (pdf 2.9 mb)

2015 (pdf 8.9 mb)

2010 (pdf 1.7 mb)

2014 (pdf 6.9 mb)

2009 (pdf 2.4 mb)

2013 (pdf 5.5 mb)

2008 (pdf 3.2 mb)

2012 (pdf 3.8 mb)

2007 (pdf 2.3 mb)

The multimodal 2016 Corridor Capacity Report includes an online story map that lets readers explore data from the report in a visual format using interactive tools.

The multimodal 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 multimodal Corridor Capacity Report, a data Appendix (pdf 13.6 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 5.9 mb) is a comprehensive methodology tool for implementing system performance measurement as part of WSDOT's accountability initiatives and the federal
Moving Ahead for Progress in the 21st Century (MAP-21) requirements.

Mobility updates

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 See the Gray Notebook Subject Index for historical documents.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 & 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.

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.

Past Congestion Publications