Development of Safety Performance Function Based on the Vehicle Automation Levels

Vehicle automation improves highway safety by integrating advanced driving assistance systems (ADAS) into modern vehicles. These systems, such as automatic braking, lane keeping, and adaptive cruise control, not only prevent collisions but also contribute to a significant reduction in fatality rates on highway systems. Traditionally, transportation agencies and researchers have relied on safety performance functions (SPFs) and crash modification factors (CMFs) to identify high-risk road segments and establish the benefit of deploying a particular countermeasure. These analytical approaches are essential for network screening and safety analysis, as they quantify the relationship between roadway characteristics, traffic volume, and crash occurrences. Despite these advancements, studies calibrating SPFs for various ADAS technologies to assess the safety potential of ADAS technologies in terms of crash frequency and injury severity remain limited. To address this gap, the current research aims to develop SPFs and CMFs for various ADAS technologies. As a result, this work seeks to enhance our understanding of how different automated systems contribute to roadway safety and provide more accurate tools for network screening and targeted safety interventions.