RAMP METERING FOR THE 21ST CENTURY : MINNESOTA'S EXPERIENCE

The Minnesota Department of Transportation (Mn/DOT) employs several innovative, leading- edge techniques that lend themselves to the philosophy of doing more with less. One key aspect of Mn/DOT's traffic management resources is the use of freeway ramp meters. Freeway ramp meters made their debut in the Minneapolis/St. Paul Metropolitan area in the early 60's. Ramp metering evolved over the next 25-plus years in Minnesota and has proven to be very effective in achieving and maintaining desirable vehicle speeds and volumes along the freeway system. Federal, State, County, and three local cities have joined forces to implement a corridor management concept that is addressing congestion on both freeways and local roads through traffic signal and ramp meter coordination. In an effort to align freeway traffic management strategies with the goals and objectives of city and county authorities, several changes to ramp metering and to traffic signal operations are currently being tested under the Integrated Corridor Traffic Management (ICTM) project. ICTM is a Federally funded Intelligent Transportation System project that combines teamwork resources, and technology to address congestion problems in the 494 Transportation Corridor. The projected is expected to improve travel times, reduce delays at ramps, provide motorists with route choices and increase safety. This paper will focus on the ramp metering system (ICTM-RMS) developed within the Sydney Coordinated Adaptive Traffic System (SCATS). SCATS provides traffic adaptive ramp metering and traffic signals. It will highlight RMS features being tested and present preliminary evaluation results