Operational Effect of Allowing Single Occupant Hybrid Vehicles into High Occupancy Vehicle Lanes

In an effort to reduce the environmental impacts of automobile travel, legislatures across the country are considering laws that would allow single occupant hybrid vehicles to use highoccupancy vehicle (HOV) lanes. Over time, single occupant hybrid vehicles could increase congestion in HOV lanes to such a degree that the travel time incentive would be lost. This paper presents a microscopic simulation method to examine the possible effects of a proposed California state hybrid-HOV law that would allow single occupant hybrid vehicles into the state’s HOV network. The results from simulating a 12-mile by 16-mile freeway network around Irvine, California under several travel demand scenarios show that the policy would not have a significant impact on HOV lane operations in the study area. While the addition of single occupant hybrids might only have a modest impact on short-run HOV lane operations, policy implementation opens the door to more difficult long-term policy questions. TRB 2006 Annual Meeting CD-ROM Paper revised from original submittal.