This study presents two models for proactive Variable Speed Limit (VSL) control on recurrently congested freeway segments.
- BASIC PROACTIVE CONTROL MODEL: a calibrated macroscopic traffic flow model was employed to predict traffic conditions over the target time horizon and to provide the essential information for the VSL optimization module.
- ENHANCED PROACTIVE CONTROL MODEL: To fully capture the complex interrelations between speed and density, this study has further adopted a special algorithm to improve the accuracy of the predicted traffic conditions over the target time horizon for proactive VSL control
To compare the proposed VSL models with the No-control scenario, the study designed the following four scenarios:
- Scenario-1: the basic proactive model with the objective of total travel time minimization;
- Scenario-2: the enhanced proactive model with the objective of total travel time minimization;
- Scenario-3: the basic proactive model with the objective of speed variance minimization; and
- Scenario-4: the enhanced proactive model with the objective of speed variance minimization.
Table Performance Comparison between Different Scenarios
Ave. # of Stops
Ave. Travel Time (s)
7:00-8:00 Ave. Travel Time (s)
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