Predicting driver response to road departure and attempted recovery is a challenging but essential need for estimating the benefits of active safety systems. One promising approach has been to mathematically model the driver steering and braking inputs during departure and recovery. The objective of this paper is to compare a model developed by Volvo, Ford, and UMRTI (VFU) through the Advanced Crash Avoidance Technologies (ACAT) Program against a set of real-world departure events. These departure events, collected by Hutchinson and Kennedy, include the vehicle's off road trajectory in 256 road departure events involving passenger vehicles. The VFU-ACAT model was exercised for left side road departures onto the median of a divided highway with a speed limit of 113 kph (70 mph).
At low departure angles, the VFU-ACAT model underpredicted the maximum lateral and longitudinal distances when compared to the departure events measured by Hutchinson and Kennedy. Two sets of driver parameters were used to simulate the trajectories, and similar results were seen for the two sets of driver parameters. Vehicles experienced control loss at higher departure angles, particularly in cases modeled with more aggressive driver steering. Maximum lateral and longitudinal distance tended to be overpredicted at high departure angles.
This study is part of a larger study that will use the VFU-ACAT driver model to simulate expected benefits of Lane Departure Warning (LDW) and Lane Keeping Assistance (LKA) systems.