Researchers have concluded that high occupancy vehicle (HOV) restrictions in the San Francisco Bay area significantly increase demand on other lanes and cause a net increase in overall congestion delay, theNewspaper.com
Researchers at the University of California, Berkeley and California State University, East Bay measured and analyzed four-and-a-half years worth of speed and travel time data from 2001 to 2005 on 100 miles of the 101 Freeway. The HOV/carpool lane restrictions on that stretch of the 101 are in effect eight to 10 hours a day.
The study found that at 60 MPH, an HOV lane has a maximum flow of 1600 vehicles per hour compared with 2000 for other lanes. The increased demand imposes a twenty percent capacity penalty on other lanes.
The study also concludes that commuters did not increase carpooling as a result of increased delays in the general purpose lanes either in the short term or in a long-term analysis.
Study authors Jaimyoung Kwon and Pravin Varaiya found that overall congestion would be reduced by eliminating the HOV lane, but only with effective on-ramp metering during congested periods, theNewspaper.com