Evaluating longitudinal speed control dynamics approaching work zones: the impact of visual-auditory interventions

Current safety evaluations of highway work zones often focus on cross-sectional speed compliance, overlooking continuous deceleration dynamics. This study evaluates how multimodal warnings combining visual markings and auditory alerts affect spatial deceleration behaviors.

Using a driving simulator, continuous vehicle trajectories were analyzed using a linear mixed-effects model with spatial interaction terms to account for individual driving habits and examine the effects of different warning interventions.

The results show that physical barricades and mandatory speed limits largely determine maximum deceleration and absolute speed reduction, regardless of warning type. However, multimodal warnings significantly smooth the microscopic deceleration process. By extending reaction times, they reduce panic hard braking and lower peak negative jerk. Furthermore, while isolated auditory alerts are subject to driver adaptation in far-field zones, multimodal combinations effectively counteract driver laxity in high-workload bottleneck segments, reducing the trajectory speeding exposure rate to 39.9%.

These findings indicate that multimodal warnings enhance safety primarily by smoothing longitudinal driving trajectories rather than altering absolute braking limits, providing quantitative evidence for spatially differentiated warning layouts.