Influence of Wrong-way Driving (WWD)-Related Dynamic Message Signs (DMS) on Traffic Behavior

Abstract: Wrong-way driving (WWD) crashes, occurring when vehicles travel against traffic, often result in severe injuries or fatalities. Despite full access control, freeways are vulnerable to these incidents. Traditional traffic control devices and advanced Intelligent Transportation System (ITS) applications have been implemented to mitigate WWD incidents, especially on freeways. Transportation agencies have been using Dynamic Message Signs (DMS) to alert right-way drivers in real time when WWD incidents are detected. However, their effectiveness in alerting right-way drivers during real-time WWD events has scarcely been evaluated. This study aims to analyze driver reactions to WWD-related DMS activations on freeways using real-world traffic speed data from the Regional Integrated Transportation Information System (RITIS) and SunGuideTM incident data. The analysis focused on traffic speed changes near DMSs during WWD events, examining patterns within freeway lanes and segments (full approaches). Statistical methods, including Z statistics and linear regression, assessed the significance of speed changes linked to WWD-related DMS activations and the influence of roadway and environmental factors. Results indicate a consistent pattern of traffic speed reductions in 74.3% of WWD events during DMS activations, with significant speed drops in 36.5% of events at a 95% confidence interval (CI). The overall mean traffic speed decreased significantly during DMS activations, demonstrating the effectiveness of DMS in positively influencing driver behavior. Factors such as the number of lanes and seasonal variations also influenced speed change patterns. Based on the results, this study recommends various countermeasures for safely responding to WWD incidents on freeways in real time.