A cooperative control method for safer on-ramp merging process in heterogeneous traffic flow

Area of Science:

• Traffic Engineering
• Intelligent Transportation Systems
• Control Theory

Background:

• On-ramp areas are critical conflict zones with frequent traffic accidents.
• Connected and Automated Vehicles (CAVs) offer potential solutions for enhancing merging safety.
• Heterogeneous traffic flow presents unique challenges for merging processes.

Purpose of the Study:

• To propose a cooperative control method for safer on-ramp merging in mixed traffic.
• To develop a two-layered gap selection function for virtual platooning.
• To evaluate the safety and efficiency of the proposed control method.

Main Methods:

• Describing the gap selection process for ramp vehicles to form virtual platoons.
• Utilizing Vehicle Bonds (VB) to define inter-vehicle connections within platoons.
• Implementing a two-layered gap selection function prioritizing safety and fairness.
• Employing Time Exposed Time-to-Collision (TET), Cumulative Risk (CR), and Conflict-Potential Mergence Ratio (CPMR) for evaluation.

Main Results:

• The gap selection control advances merging positions, reducing merging risks.
• Significant enhancements in on-ramp merging safety were observed without compromising traffic efficiency.
• With a 10-90% CAV penetration rate, average TET and CR decreased by 30-60% compared to the non-control group.
• In a pure CAV environment, safety improvements reached approximately 90%.

Conclusions:

• The proposed gap selection control method effectively enhances on-ramp merging safety in heterogeneous traffic.
• The control strategy is robust across various flow rates and speeds, with optimal performance in communication areas of 100-200m.
• This approach offers a promising solution for mitigating accidents in high-risk merging zones.