Policy Options to Promote Car-sharing while Suppressing Private Car Usage: An Analysis by Trip Distance

Car-sharing could have substantial benefits. However, there is a lack of evidence about if more people choosing car-sharing would reduce private car usage or, instead, shrink public transport demand. This work aims to bridge the gap by first studying car-sharing choice behavior via a mode choice analysis and then revealing the pattern of modal split changes via a scenario analysis. Policy implications are subsequently obtained on the possible measures that could effectively bring down private car usage. The case study is Taiyuan-China; stated and revealed preference data are both collected. Mixed nested logit models are developed to study the combined SP/RP data. The analysis is conducted separately for a shorter trip case (2km to 5km) and a longer trip case (more than 5km) to examine if results would differ by distance. It is found that raising the cost of private car usage (travel cost, parking cost) should be prioritized for shorter trips since car is more difficult to be substituted when trip distance increases. Shorter trips also need such direct measures to help suppress the demand for private car when promoting a car-sharing service; otherwise car-sharing would attract more bus users instead. Longer trips need a more effective solution to bring down private car usage and that is discovered as making car-sharing service more appealing so that it can serve as a practical substitute to private car. A number of informative indicators (e.g. value of travel time savings, direct and cross point elasticity) are also derived to enrich the findings