Traffic Responsive Ramp Metering in a Coordinated System

Surface transportation in the United States faces a number of problems. Despite the fact that the United States has one of the best roadway systems in the world, the mobility is declining. Inefficient movement of vehicles reduces productivity, wastes energy, increases emissions, and threatens the quality of life we enjoy. Intelligent Transportation Systems (ITS) provide tools that can assist in addressing current surface transportation problems. ITS provides emerging and advanced technologies in the area of communications, information processing, controls and electronics for transportation needs. Implementation of these technologies regains support of transportation agendas, in an attempt to solve today\u27s traffic problems. In 1992 the Wisconsin Department of Transportation began implementing a Freeway Traffic Management System throughout the Milwaukee area. This system is known as the MONITOR program. This implementing process is part of an ongoing growing system. One element of this system includes the installation of ramp metered signals. In the early stages of implementation, the ramp metering was setup to operate locally but not as a coordinated system. This local operation is still the current method of operation. This local type of ramp metering is adequate for recurrent congestion but is by far inadequate for non-recurrent congestion. The reason is incidents that restrict capacity may occur downstream from a locally controlled ramp meter. The most traffic adaptable type of ramp metering for local recurrent congestion, system congestion and in response to downstream incidents is a coordinated ramp metered system. Currently WISDOT does not operate any of the ramp meters as a coordinated system. The goal of this research paper is to discuss the current ramp meter operation and implement a coordinated system on a small test segment of the I-894 I HWY 45 freeway. During the implementation and setup of the coordinated system, data will be collected to compare the system performance before and after implementation. This may help in determining if a.coordinated ramp meter system is beneficial. When completed this research may be helpful to WISDOT for future policy and operating considerations pertaining to their Freeway Traffic Management system