Poisson Multilevel Methodology of Bicycle Levels of Service for Road Networks

Methodologies for bicycle levels of service have been developed for urban and suburban road segments, as well as for rural road segments. Today, however, the utilitarian (commuter) cyclist requires access to urban, suburban, and rural environs to travel safely between home and work. To complement bicycle level-of-service methodologies that incorporate mental stressors in road segments, this study developed a bicycle level-of-service methodology that incorporates physical stressors in road networks with the greatest influence on the frequency and the severity of cycling injuries from bicycle–motor vehicle collisions. To do so, the methodology integrates output from two different statistical models. To model the frequency of bicycle–motor vehicle collisions on all road segments (n = 65) in a regional road network, a Poisson model was used. To model the severity of all bicycle–motor vehicle collisions (n = 25) on the road segments in a regional road network, a multilevel model was used. To complete the Poisson multilevel bicycle level-of-service methodology, the outputs from the Poisson model of the frequency of bicycle–motor vehicle collisions and from the multilevel model of the severity of bicycle-motor vehicle collisions were used as the inputs in a geographic information system. Through analysis of the study area road network, samples of utilitarian cycling routes that minimize distance alone and that maximize safety alone were selected to quantify the benefits and the costs to utilitarian cyclists in terms of time and safety for both selections.