Safety research and modeling has traditionally been divided into two separate realms – that of the vehicle and that of the road. Because crashes are caused by a variety of factors – the driver, the vehicle, and the road – and their interactions, it is ideal to look at the larger picture of transportation safety. Modeling is a useful test bed for new technologies and improvements; and greater fidelity in safety modeling will allow designers to see the potential impact of an infrastructure or vehicular change before implementing it. To make the greatest impact, civil and mechanical engineers must work together to capture the entirety of the transportation system, tying together elements of traffic flow, driver behavior, and vehicle dynamics.
For this project, made possible by a University of Virginia Seed grant, an interdisciplinary model for was developed testing safety technology by linking VISSIM, a civil engineering traffic flow simulator, and MADYMO, a mechanical engineering vehicle dynamics simulator. Traffic conflicts were chosen as a surrogate for crashes due to the limitations of simulation and the rareness of crashes. The outputs of the model are the number and type of conflicts along with severity metrics and the probabilities of different injury types. Only rear-end crashes have been studied so far, but the model could be extended to cover other crash types and other explanatory variables. The model was validated on crash data from Route 50 in northern Virginia before being used for a demonstration on testing the efficacy of forward collision warning, pre-crash braking, and autonomous pre-crash braking. It is demonstrated that existing models can be tied together to examine transportation safety in terms of the roadway, vehicles, and driver and test new technologies and infrastructure improvements.