Study on the Improvement of the Safety Distance Model Based on Speed Difference

Abstract

Considering the diversity and random of the factors in traditional safety distance model, the deceleration and some time parameters in the braking action of the modified model were quantified first. When the following car moved slowly than the car ahead, it usually tailgated with speed modes. This case was considered in the modified safety-distance model. The model is proven to be higher accuracy by calculating and emulation analysis. Research shows that smaller speed difference, less the safety-distance it needs to keep, but it becomes insignificant when the following car is slower than the car ahead. There is greater uncertainty in rear-ending accidents for overlooking the fact that the car following with speeding in the traditional model.