A primary goal of crash reconstruction (or collision avoidance system) is to determine whether a crash is avoidable or not. A prerequisite for the determination of avoidance is knowledge of the time that is available to a driver. In a path intrusion crash scenario, a method to determine the time available for a major road driver is to know the time a minor road driver accelerated before impact. This research is an attempt to model the time based upon acceleration distance.
The current study involved two parts. Part one was a naturalistic study of driver acceleration behavior at two-way-stop controlled intersections. In part two, ten drivers with instrumented vehicles were asked to drive a route that included four acceleration runs at two-way-stop sign control intersections. In the naturalistic study, the accelerations were measured using video recordings and videogrammetry at known distances.
The purpose of the research was to gather acceleration data that was used to develop mathematical models that offers crash reconstructionists (and collision avoidance systems) the time duration of an acceleration given the distance to travel and the location of the accelerating vehicle along the acceleration profile.
The result was that drivers accelerate at a non-linear rate from two-way-stop controlled intersections. Duration of acceleration was best modeled with respect to distance (time
versus
distance) with a power function. Acceleration distance
versus
time and speed
versus
time models are also offered. These results were compared to results from prior acceleration research that was conducted at similar and different intersections.