Bicycle stress level as a tool to evaluate urban and suburban bicycle compatibility

The available information for establishing criteria to determine the bicycle compatibility of roadways is limited. Existing bicycle-compatible roadway procedures do not provide a complete picture of bicycling conditions from the different points of view of the various types of bicyclists. such procedures also fail to account for the varying levels of difficulty bicyclists experience under different traffic conditions. The authors have employed 'bicycle stress level' as a method to supply this missing information and thus provide the full range of criteria needed to determine the bicycle compatibility of roadways. Bicyclists on streets seek to minimize mental stress. They want to avoid conflict with motor vehicles and the strain of having to concentrate for long periods of riding along narrow, high-speed, high-volume roads. The authors have established bicycle stress levels ranging from 1 to 5 to account for traffic variables of volume, speed, and curb lane width. Level 1 indicates no problems for bicyclists; Level 5 suggests major problems. The highest and lowest stress levels are based on a thorough review of traffic engineering literature, the rationale being that if conditions are bad for motorists, they will be worse for bicyclists. Stress Levels 2 to 4 were prorated between the two extremes. The stress levels defined in the present study were validated by a group of volunteer bicyclists who watched videotaped segments showing a wide range of on-street traffic conditions and rated them according to the traffic variables described above.