A new access density definition and its correlation with crash rates by microscopic traffic simulation method

Area of Science:

• Transportation Engineering
• Traffic Safety Analysis
• Roadway Management

Background:

• Effective access management is crucial for enhancing highway safety and reducing potential crashes.
• Understanding the safety impact of various access types, typically measured by crash rates, is essential for informed decision-making.

Purpose of the Study:

• To propose a novel definition of access density that incorporates traffic speed variations influenced by different access types.
• To improve the correlation between access characteristics and roadway safety metrics.

Main Methods:

• Utilized microscopic traffic simulation software (TSIS-CORSIM) to determine traffic speed variations.
• Developed a new 'Access Weight' metric based on speed variations, and subsequently a new 'access density' definition.
• Compared the proposed access density with existing definitions by analyzing correlations with crash rates on a suburban roadway.

Main Results:

• The proposed access density definition demonstrated a stronger correlation with crash rates compared to the existing definition.
• Traffic speed variation, influenced by access types, is a significant factor in roadway safety.

Conclusions:

• The new access density metric offers a more accurate representation of roadway safety risks associated with access points.
• Findings provide valuable insights for the Federal Highway Administration (FHWA) and transportation consulting firms in regulating roadway design and management.