2021 AAAM Student Symposium Best Paper Award

Abstract

All roadside hardware, such as guardrails and concrete barriers, are crash tested according to the American Association of State Highway and Transportation Officials’ (AASHTO) Manual for Assessing Safety Hardware (MASH) roadside hardware crash test procedures [1]. Unlike the National Highway Traffic Safety Administration’s (NHTSA) regulatory tests, MASH test procedures do not use instrumented anthropometric test devices (ATD) to assess vehicle occupant injury risk [2]. As a substitute, MASH prescribes vehicle-based metrics, such as the Flail Space Model (FSM), to assess occupant risk. Currently, MASH specifies procedures for frontal and frontal-oblique crashes, but does not specify lateral-only crashes with roadside hardware [1]. Very few studies have investigated the injury thresholds used in MASH procedures. In particular, very little is known regarding the lateral thresholds.

The goal of this study was to compare the ability of five different crash severity metrics to predict occupant injury in real-world side impact crashes: maximum delta-v (MDV), occupant impact velocity (OIV), ASI, occupant load criterion (OLC), and vehicle pulse index (VPI). The crash severity metrics were calculated from the crash pulse data recorded by the EDR. Side impact crashes from the National Automotive Sampling System Crashworthiness Data System (NASS/CDS) were used to train logistic regression models that predict moderate to fatal injuries.
Every metric predicts higher injury risks at the same metric value for unbelted occupants. Additionally, MDV, OIV, ASI, and VPI predict higher injury risks at the same metric value for occupants in a laterally-oriented crash. The final models for MDV and OIV performed best on the test dataset, with an F1 score of 0.74.

Dean, ME, Gabauer, DJ, Gabler, HC, "Evaluation of Roadside Crash Injury Metrics in Side Crashes Using Event Data Recorder Data." AAAM Student Symposium. 2021. Indianapolis, Indiana.