A VII-Based System-Wide Ramp Metering Approach

Ramp metering is a conventional approach for controlling the rate of vehicles entering a freeway network and hence mitigating the negative effects of congestions such as reduced mobility and safety. Due to the constraint of current traffic condition detection technologies, detailed traffic condition information on vehicles entering and exiting the freeway system is not available to fine-tune the process of vehicles entering the freeway system. The emerging technology of Vehicle Infrastructure Integration (VII) presents a potential opportunity of developing a system-wide ramp metering system with the ability of fine-tuning the process of the vehicles entering the freeway system and hence increasing the efficiency and safety of the vehicle merging into the freeway traffic stream. In this paper, a VII-based system-wide ramp metering algorithm is proposed to obtain the traffic condition information at vehicle-level and combine the information with the queue detection, ramp utilization, and OD information for fine-tuning the vehicle entering the freeway system. In addition, queue flush and vehicle guidance are included to minimize the possibility of onramp vehicles spilling back to the arterials.