The purpose of this study is to determine how new pavement markings (central sharrows and indication of “dooring zone”) influence cyclist and motorist interactions and positioning, especially with respect to the distance cyclists travel from the parking edge line. The markings are designed to discourage cyclists from riding in the dooring-zone area and to ride in the center of the travel lane to avoid serious safety hazards. A number of safety performance parameters were used to assess whether safer conditions existed after the new treatment was installed. Safe motorist behavior was defined as: (a) motor vehicle following a cyclist with or without visible oncoming traffic in the opposing lane, and (b) motor vehicle passing a cyclist at a safe lateral distance. Safe cyclist behavior was defined as: cyclist riding in the lane position indicated by the central sharrows and outside of the dooring-zone area. The findings indicate that the central sharrows and dooring-zone markings created more favorable conditions for cyclist safety and for motorist compliance. Cyclists rode further from the parking edge line and closer to the sharrows that were marked in the center of the travel lane, and motorists were shown to be less likely to pass and more likely to follow cyclists.
Transportation Research Record
Department of Civil and Environmental Engineering

Kassim, A. (Ali), Ismail, K, & McGuire, S. (Shawn). (2018). Operational Evaluation of Central Sharrows and Dooring Zone Treatment on Road User Behavior in Ottawa, Canada. Transportation Research Record. doi:10.1177/0361198118787092