New Research On HOT Lanes

The recently released journey-to-work figures from the 2000 census reveal what many of us have long suspected: carpooling is a flop. Despite the expenditure of billions of dollars adding carpool lanes to congested freeways, carpooling declined from 13.4% of work trips in 1990 to 11.2% in 2000. Carpooling's mode share declined in 36 of the largest 40 metro areas-including highly congested Los Angeles and San Francisco. So what do we do now?... What's been missing from this discussion has been serious quantitative analysis of the tradeoffs involved. That gap has recently been filled by a little-noticed UCLA Ph.D. dissertation by Eugene Kim, "HOT Lanes: A Comparative Evaluation of Costs, Benefits, and Performance." Kim used a logit travel-demand model to estimate the comparative travel times that would come about by converting an existing HOV lane on a congested freeway to (a) a GP lane, (b) a HOT lane, or (c) a Toll lane. He also estimated long-term (20-year) costs and benefits of each alternative, as well as environmental impacts.

Thanks to George Passantino