Operation analysis of freeway mixed traffic flow based on catch-up coordination platoon

Area of Science:

• Intelligent Transportation Systems (ITS)
• Traffic Engineering
• Autonomous Driving Technology

Background:

• Connected and Autonomous Vehicles (CAVs) are emerging technologies in Intelligent Transportation Systems (ITS).
• A significant transition period exists before full CAV adoption, necessitating analysis of mixed traffic flow impacts.
• Understanding CAVs' effects on traffic dynamics and safety is crucial for infrastructure planning.

Purpose of the Study:

• To develop and analyze a platoon cooperation strategy for mixed traffic flow.
• To evaluate the impact of CAV market penetration rate (MPR) on traffic flow characteristics.
• To assess the influence of CAVs and platoon strategies on traffic safety.

Main Methods:

• Development of a platoon cooperation strategy based on the "catch-up" mechanism.
• Simulation analysis of mixed traffic flow incorporating varying CAV market penetration rates.
• Evaluation of traffic flow fundamental diagram, traffic oscillation, and surrogate safety measures (SSMs).

Main Results:

• Increasing CAV MPR enhances road capacity and significantly reduces traffic oscillations.
• The proposed platoon strategy further increases road capacity and dampens shockwaves.
• While CAVs reduce some risks, the platoon strategy increases collision risk and conflict severity according to specific SSMs.

Conclusions:

• CAVs positively impact traffic flow efficiency and stability, especially with platoon strategies.
• Traffic safety analysis reveals complex interactions; while overall risk may decrease, specific conflict scenarios can intensify.
• Further research is needed to optimize CAV platoon strategies for enhanced safety in mixed traffic environments.