Signal Operations Research Laboratory For Development and Testing of Advanced Control Strategies , Phase II

The corridor simulation environment with the capability of modeling various types of traffic control strategies as the external control modules is of critical importance in developing and improving corridor management strategies. In this research, a microscopic network simulation model, Vissim, is used to develop such an environment, where the new stratified Mn/DOT metering algorithm was simulated using the 169 freeway and its performance was compared with those of the fixed-metering method. Based on the analysis results, an alternative approach to determine the minimum metering rate for each entrance ramp was developed and coded. Further, an adaptive approach to automatically coordinate a freeway meter with the adjacent intersection signal is also developed and evaluated using the corridor simulation environment. The evaluation results with a sample network consisting of one intersection and one entrance ramp show a clear advantage of the proposed method in reducing the overall delay at the ramp-intersection area, while producing higher or compatible total vehicle-miles compared with the conventional intersection-control methods, i.e., pre-timed and actuated, without employing ramp metering. The corridor evaluation environment developed in this study can be used for future studies including the continuous enhancement of the stratified metering algorithm to take advantage of the maximum allowable waiting time, automatic identification of the most effective metering strategy depending on prevailing traffic conditions, and extension of the adaptive coordination method to multiple intersections adjacent to a freeway entrance ramp. This report represents the results of research conducted by the authors and does not necessarily represent the view or policy of the Minnesota Department of Transportation and/or the Center for Transportation Studies. This report does not contain a standard or specified techniques. Aswegan, and the administrative support provided by Ann Mclellan is deeply appreciated.