SOUTHEAST EXPRESSWAY RESERVED LANE FOR BUSES AND CARPOOLS

The northbound left lane of the heavily congested Expressway was reserved on a voluntary, unenforced basis, for buses and 3-or-more-occupant carpools during the morning peak period 6:30-9:30 A.M. This was Phase 1 of an effort to raise the vehicle occupancy of the highest volume roadway in Massachusetts in anticipation of several years of reconstruction of all bridge decks on and over the Expressway. Phase 2 of Reserved Lane operation began by carrying the Reserved Lane through a three-lane construction bottleneck and detour at its northern end. In Phase 3, the 3-or-more-occupant per vehicle requirement was enforced. The operation of the voluntary lane in Phase 1 increased carpooling on the Expressway by 38 and 72 percent in the 3 hour A.M. peak period and peak hour respectively. In the peak hour, 184 more people were carried in 429 fewer vehicles. Fifty percent of the peak hour persons using the Expressway during Phase 2 were carried in the free flowing Reserved Lane. The entire Expressway operated in Phases 1 and 2 with less congestion than before, no increase in accidents and no measurable impact on alternate surface street traffic attributable to the Lane itself. During the Phase 1 peak period, over 50 percent of the reduction in autos on the Expressway was accounted for by increased vehicle occupancy on the Expressway itself. Rail transit ridership in the corridor increased. Indicating the complementarity of alternative high occupancy modes in a high volume corridor. Express bus ridership increased only slightly. During the only two weeks of operation of Phase 3, travel times in the general-purpose lanes increased and varied from day to day. Despite continually increasing shifts to alternate modes the public outcry and concern of public officials regarding the deteriorated travel conditions in the general-purpose travel lanes led to a decision to terminate the project after two weeks of enforced operation. Phase 3 results are presented in the paper, but are not felt to represent equilibrium results. /Author/