Evaluation of New Coordinated Feedback-Based Freeway Ramp Metering Strategy Using Macroscopic and Microscopic Simulation Models

In this paper, C-MIXCROS and D-MIXCROS, two new feedback-based coordinated ramp metering strategies that explicitly consider ramp queues are proposed and then evaluated using both macroscopic (Rutgers Macroscopic Simulation Environment) and microscopic (PARAMICS) simulation model (on an 11-mile-long corridor of I-295 in South Jersey) under different demand conditions. In addition to the newly proposed coordinated ramp metering strategies, a well-known coordinated strategy (METALINE (5)) and three other local strategies (ALINEA (6), New Control (1), and MIXCROS (1)) are also implemented using the same network and results are compared. The proportional-derivative state feedback control logic and direct regulation of on-ramp queues are employed in the derivation of this new proposed coordinated ramp metering strategy. The results from the microscopic simulation are consistent with the macroscopic simulation, where D-MIXCROS and C-MIXCROS both perform better than all other control strategies tests for all the demand scenarios. The deteriorating effect of large on-ramp queues on the total travel time is especially observed for METALINE results; the total travel tome is approximately 22% greater than those of C-MIXCROS results. MIXCROS (1) is also successful in keeping the on-ramp queues at a reasonable level for each ramp. However, because it is a local ramp metering strategy, coordinated versions of MIXCROS are observed to be more beneficial both for the ramp system and at the network level.