Examination Of Factors Affecting The Frequency, Response Time, And Clearance Time Of Incidents On Freeways

Traffic incidents are the primary cause of non-recurrent congestion in urban areas, resulting in reductions in roadway capacity and significant safety hazards to other motorists, as well as first responders. Many communities have initiated incident management programs that detect and respond to incidents and restore freeways to full capacity by clearing the incident scene as soon as possible. In the Detroit metro area, the Michigan Department of Transportation (MDOT) operates a Freeway Courtesy Patrol (FCP) program as part of its larger freeway incident management program from the Michigan Intelligent Transportation Systems (MITS) Center in downtown Detroit. The MITS Center maintains a series of databases that detail freeway operations, as well as the activities of the FCP. However, these databases are independent of one another and no research has concurrently examined the interrelationships between freeway operations and the services provided by the MITS Center. This study aims at analyzing operations on the Detroit freeway network. This study assesses the data maintained by the MITS Center and involves the development of a software interface that was used to combine data from these various sources. These data include traffic flow information obtained from side-fire sensors, as well as data related to FCP operations in the Detroit freeway network. In addition to linking these independent data sources, preliminary data analyses are conducted in order to identify important factors influencing the incident clearance time. A comprehensive database along with traffic flow characteristics is prepared and statistical analyses are conducted to identify important factors that impact the frequency and duration of incidents on various freeway sections in Detroit metro area. It allows the consideration of the effect of various site-specific variables across different locations as well as the transferability of developed models. Consequently, this assessment highlights different areas of opportunity, uncovers the underlying strong and weak areas of existing MDOT freeway incident management program and offers important directions for the possible improvement that can collectively result in the development of better freeway traffic operations in Detroit metro area