Improving Freeway Operation with Ramp Metering Control Using Connected Vehicles as "Floating Sensors"

Adaptive ramp metering is designated to release on-ramp flow based on the level of congestion on the mainline freeway. This technique theoretically sounds to alleviate recurring and non-recurring congestions, but greatly relies on prompt on-ramp and mainline freeway traffic detections of speed and flow variations. However, the traditional fixed detectors are a barrier to the goal because of their incapability of quickly capturing the spatiotemporal patterns of congestion. With the emerging connected vehicle (CV) technology, it potentially provides a solution when the technology makes vehicles to become "floating sensors" that seamlessly cover the concerned highway over continuous time horizon. As a cost-effective, risk-free approach to quantitatively capture the CV-affected driver behaviors, the developed method is to explore the synthesis on the operation of ramp meters at a real-world freeway facility with CV support. The simulation results suggest positive benefits of improving freeway operation with ramp metering facility in CV environment.