The Impact of High-Occupancy Vehicle Lanes on Commuters: Field Evidence
29 Pages Posted: 28 May 2020 Last revised: 19 Oct 2020
Date Written: March 31, 2020
Governments are actively investing to alleviate traffic congestion. Starting from the 1970s, a common policy has been to introduce high-occupancy vehicle (HOV) lanes, that is, traffic lanes exclusively reserved for vehicles with more than one occupant. Following the introduction of HOV lanes in several countries, their effectiveness has been the topic of heated debates. In this paper, we have a unique opportunity to empirically examine the impact of introducing HOV lanes on carpooling. In October 2019, the Israeli government has decided to introduce three HOV lanes. In this context, we have access to traffic and carpool data — from Waze (the free GPS navigation app owned by Google) — both before and after introducing the HOV lanes. We can thus rigorously quantify the impact of introducing an HOV lane on carpool intent and adoption. We also study refined questions around the effectiveness of different types of HOV lanes (2+ versus 3+), the impact at different times of the day, and the behavioral effect on commuters (e.g., strategically adapting commute times). Our study shows that the introduction of the HOV lanes led to a median time saving during rush hours of 5.7-15.7 minutes and increased the carpool rates by hundreds of percent for some routes. Interestingly, we find that the new HOV lanes have a global impact as they also raised the carpool rates for routes unaffected by the HOV lanes. This effect can be explained by the increased awareness of the public about the opportunity of carpooling.
Keywords: Carpooling, Public Policy, Natural Experiment, Reducing Commute Time
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