Impact of Weaving Segment Configuration Designs on Drivers’ Acute Driving Stress: A Case Study on Houston Freeway Weaving Segments

Abstract

Weaving turbulence on freeways significantly increases the demand for complex driving maneuvers, leading to high driver stress. This study explored the impact of freeway weaving segment configuration designs on drivers’ stress attributed to complex vehicle maneuvers in dynamic traffic. An on-road driving test was conducted to measure healthy, young drivers’ heart rate variability, a biomarker of driving stress, while they performed various freeway weaving maneuvers under different traffic conditions. Statistical analyses were conducted to identify specific weaving maneuvers that triggered high- and medium-level driver stress. The probability distributions of the heart rate variability were estimated and the probabilities of high- and medium driving-stress were determined. Results indicate that intense demand of vehicle maneuvers significantly increases drivers’ stress, especially in the driving scenarios, where two-lane changes were required and the base length of weaving segments were shorter than 400 m or longer than 700 m under medium traffic, or the non-weaving segments were under medium traffic. The baseline driver stress probability is 3.34%. This grew dramatically to more than 60% under the driving scenarios. The results of the study concluded that two-sided weaving segment type, the shorter base length of weaving segments, and medium traffic, are the determinants for a higher likelihood of the driving stress.