While a large body of literature shows that car share encourages low car ownership, the evidence is rather limited in the context of different types of car share (fleet-based versus peer-to-peer) and geographic settings (inner versus middle suburbs). This study was an in-depth investigation of the impact of (round-trip) car share on ownership, including forgone or delayed purchasing across different car share systems. An online survey was conducted with car share members (n = 651) and non-members (n = 290) in Melbourne, Australia. All respondents had a shared car available within a 10-min walk of their home. The first part of the paper compared member and non-member householders (socio-demographically and geographically adjusted) and found that members owned significantly fewer cars than non-members. In the second part of the paper, a quasi-longitudinal comparison of car share members was conducted. One in three households reduced car ownership, and most reductions occurred in the year prior to joining car share. Fleet-based car share members reported a larger reduction in car ownership compared to peer-to-peer car share members. Residents of inner and middle suburbs of Melbourne reported similar "net" reductions in car ownership, the reasons differed. Residents in densely populated inner suburbs used car share to avoid or delay car ownership while middle suburb residents used car share to avoid purchasing a second car. Findings provide valuable insights for transport policy settings which have the potential to influence car share availability and thereby support broader policy objectives to reduce dependency on private car ownership and use.

虽然大量文献表明汽车共享鼓励低汽车保有量，但在不同类型的汽车共享（基于车队与点对点）和地理环境（内城区与中郊区）的背景下，证据相当有限。这项研究深入调查了（往返）汽车共享对所有权的影响，包括在不同汽车共享系统中放弃或延迟购买。在澳大利亚墨尔本对汽车共享会员 (n = 651) 和非会员 (n = 290) 进行了在线调查。所有受访者在离家 10 分钟步行路程内都有共享汽车。论文的第一部分比较了会员和非会员住户（经过社会人口和地理调整），发现会员拥有的汽车明显少于非会员。在论文的第二部分，对汽车共享成员进行了准纵向比较。三分之一的家庭减少了汽车拥有量，大多数减少发生在加入汽车共享之前的一年。与点对点汽车共享成员相比，基于车队的汽车共享成员报告的汽车拥有量减少幅度更大。墨尔本内城区和中城区的居民报告了类似的汽车拥有量“净”减少，原因各不相同。人口稠密的内城区居民使用汽车共享来避免或延迟拥有汽车，而中郊区居民使用汽车共享来避免购买第二辆车。研究结果为交通政策设置提供了宝贵的见解，这些政策设置有可能影响汽车共享的可用性，从而支持更广泛的政策目标，以减少对私家车所有权和使用的依赖。