Roof Strength Testing and Real-World Roof Intrusion in Rollovers. Traffic Safety Facts, Research Note: Summary of Statistical Findings

摘要

This Research Note demonstrates a statistically significant relationship between the peak strength-to-weight ratio (SWR) obtained through laboratory roof strength testing and the maximum vertical roof intrusion in real-world rollovers from the National Automotive Sampling System Crashworthiness Data System (NASS-CDS). The results from both categorical analysis of vehicles with similar SWR measures and linear regression sup-port the hypothesis that passenger vehicles with a higher SWR measured in a roof crush test are likely to experi-ence less vertical roof intrusion in rollover crashes than vehicles with a lower SWR. Support for the hypothesis also remains when controlling for other possible fac-tors that may explain roof intrusion and in a sensitiv-ity analysis focused on the variance in the sampling weights. This finding complements NHTSAs previous work that demonstrated a relationship between vertical roof intrusion and injury risk in rollovers and supports the validity of SWR as a measure of roof strength.