Analysis of unconventional design for signalized and closely-spaced T-intersections

In order to increase the capacity and mitigate the traffic congestion at signalized and closely spaced T-intersections, an unconventional closely-spaced T-intersections design (UCTD) was proposed. Through setting back the main T-intersection's left-turn conflict point to the adjacent T-intersection, there is no need to change the road's land use or set additional pre-signals for the crossover segment. A two-phase scheme can be used in the main T-intersection for better performance of the heavy traffic flow. Micro simulation was developed to evaluate the UCTD's performance. In one scenario, the UCTD resulted in a reduction of average delays by 64%, stops by 46%, average stop time by 72%, average queue length by 50%, maximum queue length by 55%, and fuel consumption and related emissions by 14% compared to conventional T-intersections. Also, results found that the UCTD is suitable when the main T-intersection's traffic volume is much larger than that of the second one.