Bike Sharing and Car Trips in the City: The Case of Healthy Ride Pittsburgh

Abstract

With the ubiquitous development of mobile technologies, many cities today have installed mobile-enabled bike sharing systems - both publicly and privately owned - in an effort to nudge dwellers towards a more sustainable mode of transportation. However, there is little evidence - apart from anecdote stories - for the success of these systems. In this work we are focusing on analyzing the impact of a shared bike system on the parking demand. The latter can be thought of as a lower bound for the car trips generated towards a specific area and has implications towards potential substitution effects between driving and biking. In particular, we use data from Healthy Ride, the newly installed shared bike system in the city of Pittsburgh, combined with data we obtained from the Pittsburgh Parking Authority, and using the difference-in-differences framework we quantify the impact of the bike stations on the parking demand around them. Our findings provide evidence that even when controlling for the lost parking space (used to build the parking stations) the parking demand in the nearby areas was reduced by approximately 2%. This can have significant implications that shared bike systems can shift transportation modes, which consequently can have rippling effects for the economy and environment. In particular, our follow-up analyses indicate that the new bike share system could lead to a monthly reduction of 0.82 metric tones CO₂ emissions per square mile, or approximately 4,381 metric tones of CO₂ in the metro area of Pittsburgh!

Keywords: Shared Bike System, Difference-In-Differences