METHODOLOGY FOR ANALYZING THE INTERSTATE 495: CASUAL CARPOOLING MARKET

Casual carpooling, unlike traditional carpooling, allows commuters to share a one-way one-time ride with no further obligation. The report investigates the market for a casual carpooling system on Interstate 495 (Beltway), a four lane highway serving the suburbs of Washington, DC. Traffic counts were performed and 1,000 surveys were distributed during the morning rush hours near Tysons Corner Beltway Exit 10B, a high density employment center. The surveys asked detailed origin-destination questions, hypothetical questions concerning drivers' willingness to drive a fellow commuter or receive a subsidized taxi ride based on variations in fares and added traffic delays, and other travel data. From 200 returned surveys, 70% represented Beltway commuters of whom 50% showed possible carpooling potential. The feasibility of these carpools was tested by comparing calculated carpool travel times, drive alone travel times, and hypothetical public transportation travel times, and by examining possible monetary exchange between drivers and riders. An estimated 16% to 24% of the Beltway commuters would be willing to carpool based on trip time and cost requirements; HOV presence would increase these rates to between 18% and 38%. Survey data showed that delays between 0 and 15 minutes were much more important than fares in the range of $1 to $4 when determining the number of commuters who would be willing to casually carpool. During the morning peak period at this exit, these pools could save an estimated 30 vehicle-hours in a beltway HOV lane instead of driving alone.