The implementation of four quadrant gates, while eliminating gate arm violations by motorists, does present the potential for trapping a vehicle. A critical issue is determining gate operation time parameters to minimize the likelihood of trapping a vehicle between the entry and exit gates. This study introduces the concept of a dynamic dilemma zone road segment whose length is a function of vehicle speed profiles and driver behavior at highway-rail intersections. Car-following theory is used to model driver-vehicle parameters in the dynamic dilemma zone to enhance deterministic methodologies previously employed to determine four quadrant gate operation times. Early results from a field test site indicate this theoretical approach yields design parameters consistent with previously demonstrated techniques. (A)
Abstract