Conversion of an HOV lane to a HOT lane in Washington State allowed for a 3 to 19 percent increase in speeds in general purpose lanes despite a 2 to 3 percent increase in volumes in the general lanes.

Results of WSDOT's 2010 Congestion Report

November 19, 2010
Statewide,Washington,United States

Summary Information

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 May 2008, WSDOT opened an approximately 10 mile stretch of SR167 as HOT lanes converted from HOV lanes. On average, since the opening of the HOT lanes, HOT lane volumes have increased 19 percent since 2007 (HOV lanes), while general purpose (GP) lanes have had a 2 to 3 percent increase in volume since 2007.

  • In 2009, the users of the northbound HOT lanes during weekday (Tuesday - Thursday) morning peak period saw an average time savings of 8 minutes during the peak hour over those using the GP lanes, travelling the length of the corridor in 11 minutes verses the 19 minutes for those in the GP lanes. HOT lane users paid an average toll of $1.25.
  • In 2009, the users of the southbound HOT lanes during weekday (Tuesday - Thursday) afternoon peak period saw an average time savings of 3 minutes, travelling the corridor in 8 minutes, while those in the GP lanes took 11 minutes to travel the full corridor. The average toll for the HOT lane was $1.25.
  • Southbound afternoon peak hour speeds in the GP lanes increased 19 percent since 2007 (pre-deployment), while northbound morning peak hour speeds in GP lanes increased 3 percent since 2007.
  • Preliminary safety data indicates that collisions have decreased by 17 percent on SR167 since the beginning of HOT lane operations.

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The Congestion Report Gray Notebook Special Edition WSDOT’s comprehensive analysis of system performance on state highways,

Published By: Washington State DOT

Source Date: November 19, 2010



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congestion pricing, value pricing, variable road pricing, managed lanes

Benefit ID: 2012-00802