Safety assessment of passing relief lanes using microsimulation-based conflicts analysis.

Area of Science:

• Traffic Engineering
• Road Safety Analysis
• Transportation Planning

Background:

• Designing optimal passing lane lengths is challenging due to limited data and the reactive nature of performance-based approaches.
• Short passing 2+1 lanes require effective geometric design to balance operational, safety, and economic factors.
• Current methods for determining optimal geometric design rely on observed data, which is often insufficient.

Purpose of the Study:

• To evaluate the optimal length of passing lane sections and merging areas using microsimulation analysis.
• To address the gap in performance-based design for short passing 2+1 lanes in Poland.
• To investigate the role of geometric parameters in the safety performance of passing lanes.

Main Methods:

• Microsimulation analysis using VISSIM and Surrogate Safety Assessment Model (SSAM) software.
• Calibration and validation of microsimulation models with real traffic and crash data.
• Assessment of safety performance based on simulated traffic conflicts at various passing lane and merging area lengths and Annual Average Daily Traffic (AADT) values.

Main Results:

• Traffic conflicts can effectively serve as a surrogate measure for safety performance.
• The length of the passing lane section is a critical geometric parameter influencing safety.
• Optimizing geometric design through microsimulation provides a proactive approach to road safety.

Conclusions:

• Microsimulation is a viable tool for evaluating the safety performance of passing lane designs.
• Geometric parameters, particularly passing lane length, significantly affect the safety of 2+1 short passing lanes.
• Further research and implementation of performance-based design are needed for effective road safety improvements.