Developing a Proxy Measure for Monitoring Freeway Segment Traffic Conditions along Detours during Roadway Closures

Monitoring traffic conditions solely based on probe vehicle travel times or traffic volumes sporadically observed along roadways typically allows a transportation agency to divert the traffic reactively after a significant deterioration in traffic conditions is observed. Lack of data at key locations makes the already challenging task of monitoring traffic conditions along a lengthy detour more intractable. To address this problem, the current study developed a proxy measure that can assist transportation agencies in proactively diverting traffic to various detours during extended major freeway closures. The proxy measure was estimated using travel times observed along a ten-mile freeway segment and traffic flow departing the site. The proxy measure revealed important insights about the relationship between segment travel times and vehicle accumulation within the segment that can aid transportation agencies in proactively diverting traffic in a timely manner.