Competition or cooperation: Relationship between carsharing and other travel modes

Carsharing is becoming an important member of urban mobility systems. The relationship between carsharing and other travel modes, is the base for deciding the proportional role of carsharing. This article defines the relationship, competition or cooperation, based on whether carsharing strengthening or weakening the expected function of other travel modes from the transport system perspective. It proposes the relationship should be studied under the specific characteristics of carsharing trips (e.g., the spatiotemporal distribution), and establishes a method for evaluating the coordination of carsharing with other modes. A survey about carsharing trips was conducted, and valid data generated by 1,330 carsharing users were obtained. The spatiotemporal characteristics of carsharing substituting for subway, buses, taxis, private cars, and nonmotorized vehicles have been analyzed, and the substitution benefits were also evaluated. The results indicate that carsharing in Shanghai was mainly used for long-distance trips in suburbs during off-peak hours, which generally formed a cooperative relationship with public transit, taxis, and nonmotorized vehicles. Phenomenon that carsharing substituting for public transit mainly occurred in long-distance trips in suburbs, with an average 40–50min travel time saving. Carsharing also substituted for long-distance non-motorized vehicle trips, which improved the mobility of those travelers. To further enhance the coordination, the layout of carsharing stations and operation strategies need to be optimized to reduce the carsharing travel demands during peak hours within urban areas, and to promote carsharing as a substitute for private cars.