Motor-vehicle drivers' behavioral response to increased bicycle traffic.

Introduction: This paper investigates whether motor-vehicle driver behavior changes when there are more bicycles on the road.

Method: Data on trips on a rapidly expanding public bike share scheme in Chicago are combined with speed violations captured by a network of 79 cameras. Using weekly data from July 2014 to December 2016, violations at 26 sites where there was a considerable increase in bicycle traffic are compared with a control group of 53 locations where rental bicycles are not available.