Leveraging vehicle-based speed data in monitoring roadway safety

In developing countries like Tanzania, bus transportation is vital, yet it is challenged by speed-related crashes. To improve safety, the government deployed Vehicle Tracking Systems (VTS), though their data is often underutilized. This study evaluates VTS trajectory data to enhance inter-regional bus safety by examining speed violations across different locations and times of day. Two case studies were analyzed: a 19.2 km section of Morogoro Road and the Dar es Salaam to Mwanza intercity bus route. Using second-to-second trajectory data from ten buses, the study compared desired and actual speeds to identify violations. Results indicate that speed violations based on location are independent of time of day, whereas violations are more frequent at night on the intercity route. The findings suggest that speed enforcement can be improved by targeting nighttime violations and areas without traffic police. Immediate detection and response to incidents are also possible, thereby enhancing overall road safety.