Evaluating safety resilience in urban roadway network: Investigating the impact of different traffic control measures

The resilience of urban roadway network is crucial for maintaining effective mobility during disruptions. However, traffic safety has received limited attentions in the domain of resilience assessment. The study introduces the concept of safety resilience, which integrates traffic safety consideration into resilience research. Unlike traditional resilience that primarily focuses on traffic efficiency metrics, safety resilience is defined as a network ability to maintain and restore safety performance under disturbances by evaluating real-time traffic risk. The study presents the evaluation of safety resilience based on traffic conflicts at intersections and on roadways and explores the impact of different traffic control measures, including lane control, signal control, and connectivity improvement, on both traffic safety and efficiency. The results demonstrate that the proposed Safety Resilience Index (SRI) provides an effective means to assess network safety resilience by capturing the trade-off between safety and efficiency. Lane restrictions are found to be more suitable for road segments with high safety risk, while lane widenings are more effective in mitigating severe congestion. Signal control can enhance safety resilience but increase travel time and rear-end conflicts on roadways. Although connectivity improvement can theoretically enhance resilience from the topological perspective, it may result in worse overall network safety and efficiency. These findings underscore the need for a balanced approach that integrates both safety and efficiency in enhancing urban network resilience.