Potential Use of Puget Sound HOV Lanes by General Purpose Vehicles in Off-Peak Hours: A Summary Paper

Off-peak traffic volumes in the Puget Sound region of Washington State are increasing, and public concern about congestion during non-commute periods has caused WSDOT to re-examine the current policy of restricting HOV lanes to transit vehicles and carpools 24 hours per day, 7 days per week. In many parts of the country, HOV lanes are open to general traffic during non-peak hours. Should WSDOT adopt this less restrictive lane use policy?

This report examines the tradeoffs that a change in off-peak HOV lane usage would involve. The basic issues that are examined include the following: 
  • What congestion relief benefits would result?
  • Would these changes have adverse impacts on HOV formation and/or HOV lane compliance rates?
  • Would the off-peak use of HOV lanes by general purpose vehicles create safety concerns?
  • Would highway and transit operational problems be created?
  • What would be the monetary impacts of changing off-peak HOV lane usage?
Supported by a variety of performance graphics and statistics, the report concludes that no improvement in mobility would be obtained by relaxing the current Puget Sound HOV lane operating restrictions to allow off-peak use of the HOV lanes by general purpose traffic.
Publication Date: 
Wednesday, May 31, 2000
Publication Number: 
WA-RD 488.2
Last modified: 
10/12/2016 - 15:41
Mark E. Hallenbeck, John M. Ishimaru, Jennifer Nee.
Washington State Transportation Center (TRAC)
Number of Pages: 
Compliance, Economic impacts, Freeways, High occupancy vehicle lanes, Impacts, Mobility, Off peak periods, Policy, Traffic congestion, Traffic volume, Traffic safety.