A method to estimate the traffic impacts of at-grade light rail crossings

This research proposes a method to evaluate the impact of at-grade light rail crossings of public streets within the context of accepted traffic engineering practice. A literature review was conducted to identify concepts. A review of light rail operating characteristics was also conducted. A conceptual method was developed based on three primary measures of impact: the ratio of traffic volume to crossing capacity, the average stopped delay, and estimated queue length of motor vehicle traffic. Data was collected at 29 crossings on seven transit properties to validate the model for average stopped delay from among 22 candidates and the model for queue length from among six candidates. The successfully validated models were the Highway Capacity manual Pretimed Delay model and the arrivals during blockage plus initial discharge times two queuing model. A step by step method using these models is presented along with two examples demonstrating their application.