The Congestion Report Gray Notebook Special Edition WSDOT’s comprehensive analysis of system performance on state highways,
Washington State DOT (WSDOT) produces an annual report called The Gray Notebook, in order to evaluate their performance measurements for their highway system. The 2010 Congestion Report focuses on data comparisons between 2007 and 2009 highway capacity, usage and delay statistics. WSDOT worked to improve the operational efficiency of Washington's highways through ITS deployments such as variable speed limits, dynamic message signs, high occupancy tolling (HOT) lanes, and incident response teams, as well as through strategic expansion of roadways at reoccurring bottlenecks. The authors note that some of their findings may have been impacted slightly by the annual VMT per capita decrease of 300 miles (1.6 percent) between 2007 and 2009, a likely result of the recession and high gasoline prices.
In 2008, WSDOT implemented a new Incident Response (IR) program that provides roving patrols during peak periods, as well as being on call 24 hours a day, 7 days a week.
- While VMT rose 2 percent between 2008 and 2009, the number of incidents decreased by 8 percent over the same period.
- Of the 43,786 incidents IR responded to in 2009, 74 percent were cleared in less than 15 minutes, while 98 percent were cleared within an hour.
- In 2009 the average incident clearance time for all 43,786 incidents was 13.4 minutes, and the average roadway clearance time when roads were blocked was 19.6 minutes.