Is It Necessarily Better for More Commuters to Share a Vehicle?

Increasing private car ownership has congested urban roads and made parking more difficult, especially during the morning commute. Carpooling offers a new way to address these problems. This paper studies the dynamic departure patterns for both regular and carpooling vehicles with parking space constraints in the morning commute without the carpool lane. The results suggest that as the parking fee of the central cluster increases, the earliest time for the two types of vehicles to enter the central cluster is delayed. The increase in the proportion of regular vehicles delays the earliest time for carpooling vehicles to enter the central cluster. More commuters sharing a vehicle in the morning commute is not necessarily better. Only a reasonable level of carpooling can reduce the peak time and unnecessary time consumption on the road and effectively promote the reduction in parking fees, commuters’ travel costs, and other societal transportation costs. This research gives practical guidance and suggestions on formulating a reasonable parking fee and controlling a reasonable carpooling level.