Friday Seminar -Kitae Jang on Traffic Interactions in Freeways with Carpool Lanes

carpool lane

This Friday's TRANSOC Seminar features Kitae Jang, Ph.D. Candidate, University of California, Berkeley, presenting on "Traffic Interactions in Freeways with Carpool Lanes."

The study is concerned with the vehicular interactions that arise when carpool and regular vehicles are segregated in their own lanes. Real data show that reserving a lane for carpools on congested freeways induces a smoothing effect that is characterized by significantly higher bottleneck discharge flows (capacities) in adjacent regular-use lanes.  Thanks to this smoothing effect, we find in many cases that the carpool lanes – even when underused themselves – can benefit travelers in the regular lanes.  Ironically, the regular-use lanes are often damaging to the carpool-lane travelers. We find that the vehicle speeds in a carpool lane are negatively influenced by both growing use of that lane and diminishing vehicle speeds in the adjacent regular-use lane.  The findings do not bode well for a new US regulation stipulating that most classes of Low-Emitting Vehicles (LEVs) are to vacate slow-moving carpool lanes.  Analysis shows that relegating some or all of these vehicles to regular-use lanes can significantly add to regular-lane congestion; and that despite the reduced use of the carpool lanes this, in turn, can also reduce the speeds of those vehicles that continue to use the carpool lanes.  Constructive ways to amend the new regulation are discussed, as are promising strategies to increase the vehicle speeds in carpool lanes by improving the travel conditions in regular lanes.

The seminar will take place from 4-5 pm in 406 Davis on November 18. Please come to TRANSOC's Cookie Hour preceeding the seminar at 3:30 pm in the library.