Reliability of signalized intersection capacity under mixed traffic

The stochastic properties of signalized intersection capacities under mixed traffic conditions were analyzed, and capacity reliability of signalized intersection was defined. VISSIM simulations were employed to provide capacity data for probability distribution calibrations. Typical percentile capacities of the lanes were calculated. An evaluation method for reliability of capacity was proposed when arriving volume was considered as a random variable. The sensitivity of reliability of capacity to the mean value of the conflicting pedestrian and bicycle volumes was analyzed. The results show that the impedance effects of pedestrians and bicycles result in great randomness of the exclusive turning lane capacities, but result in relatively little changes of random fluctuations of the shared lane capacities. Normal distribution is applicable to model the probability distribution of the capacities during 10 minutes or longer intervals. With a higher arriving vehicle volume, the reliability of capacity is more sensitive to the mean values of the pedestrian and bicycle volumes.