BEHAVIORAL MODELS AND CHARACTERISTICS OF BICYCLE-AUTOMOBILE MIXED-TRAFFIC: PLANNING AND ENGINEERING IMPLICATIONS

This report addresses an important need for fundamental understanding of bicycle -automobile mixed-traffic. It presents models of (1) gap acceptance behavior and (2) bicyclist behavior at the onset of a yellow traffic signal indication, in addition to analysis of (3) coordinating traffic signals to provide progression for both bicycles and automobiles. Fundamental insights into mixed-traffic behavior are derived and applied to selected problems in mixed-traffic engineering and operations. Discrete choice (probit) models are developed for both motorist and cyclist gap acceptance behavior. An important fundamental insight from these models is that both cyclists and motorists require a longer gap when the gap is closed by a large vehicle (e.g. bus), and both will accept a shorter gap when the gap is closed by a bicycle, relative to a gap closed by a passenger car. A methodology for determining an adequate clearance interval for bicycles is developed from a deterministic model based on kinematic relations. The bicyclists behavior at the onset of a yellow signal indication are obtained. Finally, a conceptual foundation, consisting of three primary contributions, is developed for analyzing bicycle-automobile mixed-traffic progression along signalized streets.