Expansion of NASS/CDS for characterizing run-off-road crashes.

Area of Science:

• Road safety
• Traffic accident analysis
• Vehicle dynamics

Background:

• Run-off-road (ROR) crashes constitute one-third of US traffic fatalities.
• Existing datasets like the National Automotive Sampling System Crashworthiness Data System (NASS/CDS) lack crucial roadside environment and vehicle trajectory data.
• This missing data hinders the evaluation of safety systems and road design.

Purpose of the Study:

• To develop and validate a methodology for enhancing the NASS/CDS dataset.
• To create a specialized road departure database for improved ROR crash analysis.
• To inform the development of lane departure warning (LDW) systems and roadside safety hardware.

Main Methods:

• Extracted and compiled observed, measured, and reconstructed data from NASS/CDS into the NCHRP 17-43 database.
• Coded roadside environment variables from scene photographs and measured geometric data from scaled diagrams.
• Reconstructed vehicle speeds using impact dynamics and roadside object characteristics.

Main Results:

• The NCHRP 17-43 database contains 1,581 NASS/CDS cases, representing 510,154 ROR crashes.
• Analysis revealed younger drivers are more prone to overcorrection during ROR events.
• ROR crashes on roads with speed limits >65 mph exhibit higher severity than current roadside barrier test conditions.

Conclusions:

• The NCHRP 17-43 database provides enhanced data for understanding ROR crashes.
• It facilitates the assessment of driver behavior, such as overcorrection by younger drivers.
• The database aids in evaluating the effectiveness of both vehicle and infrastructure-based ROR countermeasures.