Effectiveness of a web-based intervention to encourage carpooling to work: A case study of Wellington, New Zealand

Despite the many advantages of private car travel, excessive use of the private car has many negative consequences, such as congestion and air pollution. There is widespread recognition of the need to limit the demand for private car travel through travel demand management measures, such as information and incentives. This study examines the effectiveness of Let's Carpool, an initiative aimed at increasing vehicle occupancy in the Wellington region of New Zealand, and it examines factors related to solo driving. Let's Carpool uses ride-matching software to facilitate finding a carpool match for the commute to and from work. This evaluation study among nearly 1300 registrants of Let's Carpool shows that the percentage of commuters enrolled in the scheme who carpooled as their main mode of transport for getting to work increased significantly (from 12% to 27%), while the percentage of commuters indicating they drove alone decreased significantly. The frequency of driving alone also decreased significantly. Beliefs about cost, comfort, and convenience were related to solo driving. Based on the findings, recommendations are made to further enhance the effect of carpool initiatives.

► Ride-matching information and incentives are effective in encouraging carpooling and reducing frequency of solo driving.
► Solo driving is mainly related to cost, comfort and convenience.
► Cost savings are a main reason to start carpooling.
► Lack of suitable carpool matches is main barrier to start carpooling.