To measure and report on TIM performance, data need to be collected and analyzed. Traditionally, transportation agencies have relied almost solely on their own data to monitor TIM performance, if at all. However, a transportation agency’s view of traffic incidents is often limited to specific routes, within urban areas, and specific times of the day. Incidents occur on many different types of routes statewide – both urban and rural – at all times of the day and night, and transportation agencies are usually not the first responding agency to many incidents. Therefore, relying solely on transportation agency data for TIM performance measurement provides data on only a small sample of traffic incidents in most states. Additionally, incident data often lacks the details needed to fully understand and quantify incident response (e.g., incident location, time of various responders on/off the scene, lanes blocked throughout the incident, times roadway and incident cleared). Given the manual nature of data collection, the data are often subject to quality issues. However, biggest challenges for TIM performance measurement may be a lack of data sharing across responder agencies and disparate data systems that, even if shared, challenge the integration of the data. Timeliness of data is also an issue.
Better sharing, integration, and management of data both internally at DOTs and across responder groups are needed in order to improve TIM performance measurement and management.