A Study of the Phase Setting of Exclusive Right-turn Signal under the Consideration of Vehicle Emission Characteristics

To alleviate the conflict between pedestrians and right-turn vehicles at the beginning of pedes-trian green light,the moving features of pedestrians and right-turn vehicles were investigated.A fixed-timed two-phase signalized intersection was taken as a case study in the paper.The impacts of the right-turn signal phase on the emission and average delay of vehicles were studied.The microscopic simulation software Vissim and the emission model based on VSP variables were combined to simulate different right-turn traffic volumes with three different pedestrian volumes be-fore and after implementing the exclusive right-turn signal phase.The exhaust emissions and average delays were analyzed respectively.The results indicate that the trend of vehicle emissions and average delays of before and after implementation are similar.The mean value of emissions is reduced by 9.46% and the mean value of average delays is reduced by 1 5.84%after implementation of the exclusive right-turn signal phase when the right-turn traffic volumes are below (61 5 ± 20) pcu/h.The average delays of right-turn vehicles decreased,but the exhaust emissions increased after right-turn signal im-plemented when right-turn traffic volumes are more than (61 5±20)pcu/h.