Evaluation of the Passing Behavior of Motorized Vehicles When Overtaking Bicycles on Urban Arterial Roadways

Abstract

This paper evaluates the influence of on-street bike lanes on the lateral separation between motor vehicles and cyclists when the vehicle overtakes the cyclist and investigates the relationship between the passing behavior and traffic conditions. A bicycle was instrumented with a sensor array that consisted of an ultrasonic sensor, a GPS receiver, and a video camera. A total of 5,227 passing events were recorded across different categories of urban arterials. The results showed that the facilities with on-street bike lanes provided greater separation between bicycles and motor vehicles. Passing maneuvers with lateral separation of less than 1,000 mm (3.30 ft) were observed less frequently on the facilities with on-street bike lanes. Further, it was found that, in the absence of a bike lane, a higher proportion of passing vehicles moved laterally to the left and encroached on the adjacent lane. The analysis showed that for arterial roadways without on-street bike lanes, drivers tended to provide increased lateral clearance by either changing lanes or encroaching on the adjacent lane. However, drivers' ability to perform either of these maneuvers may be restricted by surrounding vehicles.