Development and Validation of a Vehicle Dynamics Integrated Traffic Simulation Environment Assessing Surrogate Safety

A vehicle dynamics model (i.e., CarSim) was integrated with a microscopic traffic simulation model (i.e., VISSIM) for a surrogate safety assessment. This study was initiated from the idea that existing microscopic traffic simulation models could be complemented with a vehicle dynamics model having an enhanced capability of realizing the vehicle dynamics including pitch, yaw, and roll and generating realistic vehicle trajectories. In addition, a driver aggressiveness model derived from the Next Generation Simulation (NGSIM) project lane change vehicle trajectories was incorporated into the lane change vehicles in VISSIM. The resulting VISSIM vehicle trajectories were processed through CarSim to account for the vehicle dynamics and the traffic conflicts were identified through the Surrogate Safety Assessment Model (SSAM). The VISSIM-CarSim integrated simulation environment resulted in 9.5 % fewer traffic conflicts as compared with the VISSIM only approach. The results of the two conflict estimation approaches, one from the proposed VISSIM-CarSim integrated approach and the other from the VISSIM only approach, were analyzed to estimate their correlation with the actual traffic crashes. These correlations were then used to compare the effectiveness of these approaches in assessing surrogate safety. This analysis showed that the traffic conflicts obtained from the proposed approach exhibited a stronger correlation (i.e., 0.72 correlation coefficient) with traffic crashes than the existing approach did (i.e., 0.61 correlation coefficient). In addition, a cross-validation test on the confidence intervals of the correlation coefficients showed that the correlation coefficients have very tight confidence intervals (i.e., 0.02 for both cases) indicating that the newly developed vehicle dynamics model-integrated surrogate safety simulation environment is a superior and valid alternative in assessing the surrogate safety.     «

A vehicle dynamics model (i.e., CarSim) was integrated with a microscopic traffic simulation model (i.e., VISSIM) for a surrogate safety assessment. This study was initiated from the idea that existing microscopic traffic simulation models could be complemented with a vehicle dynamics model having an enhanced capability of realizing the vehicle dynamics including pitch, yaw, and roll and generating realistic vehicle trajectories. In addition, a driver aggressiveness model derived from the Next G...     »