Reducing Degradation of High-Occupancy Vehicle Lanes

Problem Statement: In California, many High-Occupancy Vehicle (HOV) lanes meet the federal standard of degradation, which is met if the average traffic speed during the morning or evening weekday peak commute hour is less than 45 miles per hour (mph) for more than 10 percent of the time over a consecutive 180-day period.   In California, HOV lanes are an effective tool to both promote carpooling and transit, and incentive the purchase of zero-emission vehicles by allowing single occupant drivers of ZEVs access to HOV lanes.  Degradation of HOV lanes reduces travel time reliability of the lanes, which then reduces the incentive for carpooling, transit and ZEV purchase.  In the long-term increasing degradation could result in the need to eliminate ZEV green and white sticker programs as a strategy to address the degradation.     Proposal: Researchers will explore best practices to address HOV lane degradation to strengthen the incentives these lanes provide for carpooling, transit and ZEV purchase.  Strategies explored, should include, but not necessarily be limited to: - Lane striping, or other infrastructure approaches that decrease unauthorized HOV lane use, and maintain or improve safety. - Innovative enforcement approaches to decrease unauthorized use, including new technologies. - Traditional enforcement approaches such as increase law enforcement.    Expected Impact and Benefits: This research should inform Caltrans and regions on best strategies to implement to reduce degradation of HOV lanes and help further state policy goals related to greenhouse gas reduction and a more efficient transportation system.