Accidents between right-turning vehicles and cyclists are a significant safety concern, particularly at intersections. These accidents are often caused by factors such as poor infrastructure design, driver error, and cyclist visibility issues. Studies have shown that a majority of these accidents occur during daylight hours and involve experienced cyclists who are riding in bike lanes or on the right side of the road. One way to mitigate these risks is to use separate signalization for cyclists, which allows them to cross the intersection without conflicting with other vehicles. However, implementing such a scheme can reduce intersection capacity, leading to increased delays and congestion. Thus, a tradeoff between safety and capacity must be made. Simulation models can help evaluate different signalization schemes and optimize intersection performance. The primary aim of this study is to use VISSIM, a microscopic traffic simulation tool, to evaluate the effectiveness of different signal phasing schemes for improving cyclist safety while maintaining intersection capacity. The specific objectives of the study are to: (1) compare the safety outcomes of different signal phasing scenarios, including all-green phases and protected left-turn phases for motor vehicles, and (2) evaluate the capacity of the intersection under each scenario. The study uses VISSIM to model the intersection layouts and simulate different separate signalization schemes for cyclists. Two types of intersection geometric layouts, three- and fourlegged, are tested with various signalization schemes. The study compares the results of the different schemes, considering the average delay experienced by vehicles and cyclists. One potential outcome of the simulation is the identification of signal phasing schemes that prioritize cyclist safety without significantly reducing overall intersection capacity. For example, the simulation may reveal that a combination of dedicated bicycle phases and protected left-turn phases for motor vehicles can significantly reduce the risk of cyclist-motor vehicle conflicts while maintaining a similar level of intersection capacity. Another potential outcome is the identification of signal phasing schemes that prioritize overall intersection capacity without significantly compromising cyclist safety. For example, the simulation may reveal that a longer overall cycle time can accommodate higher traffic volumes while still providing sufficient time for cyclists to navigate the intersection safely. Overall, the expected results of this study have the potential to inform traffic engineering and urban planning decisions related to intersection design and signal phasing. By identifying the optimal signal phasing schemes that balance safety and capacity concerns, this study can help improve the safety and efficiency of urban intersections for all road users. The study concludes that using separate signalization schemes for cyclists can significantly enhance safety at intersections without compromising intersection capacity. The study recommends the optimal separate signalization scheme for cyclists based on the objectives and compares it to other schemes. The findings of this study can inform policymakers and traffic engineers on how to improve intersection safety for cyclists while maintaining efficient traffic flow.    «

Accidents between right-turning vehicles and cyclists are a significant safety concern, particularly at intersections. These accidents are often caused by factors such as poor infrastructure design, driver error, and cyclist visibility issues. Studies have shown that a majority of these accidents occur during daylight hours and involve experienced cyclists who are riding in bike lanes or on the right side of the road. One way to mitigate these risks is to use separate signalization for cyclists,...    »