Intelligent Transportation Systems in work zones : a case study : dynamic lane merge system reducing aggressive driving and optimizing throughput at work zone merges in Michigan.

The Michigan Department of Transportation (MDOT) rebuilt a large section of I-94 in Clinton Township (a suburb of Detroit) during the 2002 and 2003 summer construction seasons. The improvements were necessary to upgrade roadway geometry and roadside hardware, to enhance safety and efficiency, and to rehabilitate deteriorating pavement. This section of I-94 provides access to and within the eastern portion of the state. The road parallels the Detroit River, a natural boundary between the United States and Canada. The work zone on I-94 extended from Michigan Route 102 (M-102) to Masonic Boulevard, a distance of about 13 miles, and involved both directions of traffic. The two-season construction project began on April 1, 2002, and ended on September 30, 2003. The project involved 13.5 lane-miles of construction, including bituminous resurfacing, concrete pavement repair, bituminous freeway and concrete ramp reconstruction, lighting installation, traffic signal installation (at the end of ramps), water main alteration, and rehabilitation of 18 bridge structures. The total project cost was $46 million. For the I-94 project, MDOT deployed a work zone Intelligent Transportation System (ITS) to help smooth traffic flow and reduce aggressive driving just prior to the transition into the construction area. MDOT selected a dynamic lane merge (DLM) system that uses electronics and communications equipment to monitor traffic flow and, as queuing increases at approaches to lane closures, to regulate merge movements and require early merging. The system, developed by International Road Dynamics Inc., used microwave radar sensors installed on five DLM trailers to detect traffic volume, vehicle speed, and detector occupancy. The main goals of the ITS system were to: (1) Reduce aggressive driving at the merge point; (2) Maximize available capacity at the merge point just prior to dropping one lane out of three; (3) Reduce capacity losses due to increased headways at the work zone taper; and (4) Enhance traveler safety. (Author/publisher)