A simulation study on traffic conflict risk under shockwave propagation at signalized intersections

Area of Science:

• Traffic Engineering
• Urban Mobility
• Transportation Safety

Background:

• Signalized intersections are critical for urban mobility but face challenges with traffic congestion and safety.
• The interplay between traffic shockwaves and conflict risk is not fully understood, hindering effective management.

Purpose of the Study:

• To investigate the relationship between traffic conflict risk and shockwave propagation at signalized intersections using simulation.
• To analyze dynamic conditions during vehicle queuing and dissipation to understand risk propagation.

Main Methods:

• Utilized vehicle trajectory data from Unmanned Aerial Vehicles (UAVs).
• Employed Simulation of Urban MObility (SUMO) software for simulation modeling, with refined trajectory data.
• Applied surrogate safety measures (SSMs) like modified time to collision (MTTC) and deceleration rate to avoid a crash (DRAC), alongside shockwave analysis (SA).

Main Results:

• Conflicts were observed as vehicles approached and stopped, with risk propagating at the tail of the queue.
• Space-time diagrams indicated that risk propagation can initiate before or concurrently with shockwave propagation.
• A correlation between conflict risk and shockwave dynamics was identified in signalized intersection scenarios.

Conclusions:

• The study uncovers a significant correlation between conflict risk and shockwave propagation at signalized intersections.
• Findings offer valuable insights for developing enhanced traffic control strategies to improve intersection safety.
• Contributes to a deeper understanding of traffic flow dynamics and safety implications in urban environments.