Dynamic Traffic Management and Safety in Urban Road Work Zones: Evidence and Implementation Priorities

At a signalized urban work zone, a lane closure may change turning capacity, pedestrian access, and queues at the next junction at the same time. The selected studies seldom assess these changes together. This critical narrative review examines 18 Chinese and international publications from 2018 to 2026, distinguishing observed traffic behavior from model-based predictions and safety-related indicators. A Toronto field study measured 1,766 signal cycles and found substantial variation in saturation flow across closure arrangements; an urban island-work-zone signal model reported queues 15.6% shorter and delay 17.2% lower in its evaluated comparison. More recent simulations include conflict-related objectives, while longitudinal site records reveal difficulties in maintaining traffic-management arrangements during construction. The available findings are informative about capacity, delays, and driver responses, but offer much less direct evidence on injury prevention or the experience of pedestrians, cyclists, transit users, and workers. The review develops a stage-based monitoring-response matrix linking site conditions to authorized actions, fallback arrangements, and follow-up checks. Field testing will need to capture traffic diverted to nearby streets, exposure along temporary routes, and the reliability of controls installed on site.