LANE VOLUME AND SATURATION FLOW-RATE FOR MULTILANE INTERSECTION APPROACH

One factor that can reduce a lane's saturation flow to less than ideal conditions is when turning vehicles share the lane with through vehic les. The slow discharge rate of the turning vehicles reduces the lane' s effective saturation flow rate in direct proportion to the percentag e of turn vehicles in it. A model is described that predicts this perc entage and the resulting saturation flow rate of the shared lane. Base d on the results of this research, it is believed that the proposed mo del accurately predicts the lane volume for any approach to a signaliz ed intersection and the uncontrolled approach to an unsignalized inter section. The model extends previous models by incorporating a sensitiv ity to both left-and right-turn movements and the probability of a lan e change into a closed-form solution. Some field data are used to vali date the proposed model.