This paper describes and evaluates the phenomenon of "instant carpooling" in the Springfield area of Northern Virginia, wherein about2, 500 strangers form ad hoc carpools each morning in order to use the high-occupancy-vehicle (HOV) express lanes on the Shirley highway to downtown Washington, D.C. and the pentagon. It presents the results of field observations on the magnitude and operation of the carpools and of informal interviews with the carpoolers. Safety and parking considerations are discussed, as well as the effect of the carpools on public-transit use. Instant carpooling is found to result insignificant savings in travel time for the passengers and drivers and in transit operating cost savings for public agencies. Planners and decision makers are urged to encourage instant carpooling as a means of enhancing the overall effectiveness of park-and-ride and HOV-lane programs. Recommendations are presented for strengthening and protecting the current springfield instant carpool operations, and the necessary conditions for replicating instant carpools elsewhere are discussed.
Abstract