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Project Type
UTRC Faculty Development Mini-grants
Project Dates
01/01/2009 - 12/31/2009
Principal Investigators
Project Status
Project Description

Car sharing programs are an innovative approach to reduce the cost and amount of vehicle travel while maintaining the benefits of automobility. On average, cars are parked unused about 95% of the time. Car sharing takes advantage of such inefficient usage by renting cars by the hour or day to program members. These shared vehicle arrangements improve the economic efficiency of auto use by reducing the costs of maintenance, parking and insurance for drivers. In addition, car sharing programs maintain the benefits of private vehicles for shopping, recreation and work-related travel at a lower cost than sole ownership of a vehicle.

Benefits from car sharing are based in part from the conversion of auto ownership from fixed costs to variable costs. As drivers pay for shared cars by the hour, they are expected to reduce their total time spent driving. Since the cars are shared, the total amount of space devoted to parking is reduced. And since the drivers only pay for the time they are using the car, the total transportation costs should decline for those who use car sharing in lieu of another vehicle. Taken together, these benefits can help fight congestion, reduce energy consumption, improve the built environment and enhance accessibility within areas served by car share programs.

This research examines these potential benefits of car sharing through a survey of car share members in Manhattan. Unlike other cities such as Portland where car sharing is used, Manhattan is unique in that it is very densely populated, most residents do not own cars and most already use transit or walk to their destinations. As such, car sharing may actually increase the total auto travel in the borough by making car ownership affordable for more households because car share members do not have to pay the high fixed costs of parking, insurance and vehicle financing. Such effects would not negate the benefits of car sharing but may suggest limits to the claims of car sharing proponents.

The significance of this research to the literature is threefold. First, the effect of car sharing on total travel is estimated. Second, the impact of car sharing on parking demand is explored. Third, the effect of car sharing on the total transportation costs for households is examined. Car sharing has the potential to be an important means to provide viable transportation alternatives that preserve mobility benefits from automobiles while lowering transportation costs, reducing the amount of land devoted to parking and limiting overall auto travel. In crowded regions like New York, such alternatives are complementary to transit, taxis and walking.