Crash incompatibility between cars, SUVs, and pickups in 2017-2022

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Introduction: The current study was conducted to update estimates of crash incompatibility between cars and SUVs/pickups in the United States. The trade-off between case driver protection and crash partner risk associated with increasing vehicle curb weight was also quantified. Method: Crashes between two 1- to 4-year-old vehicles where at least one driver was killed were extracted from the Fatality Analysis Reporting System (FARS) for two intervals, 2011-2016 and 2017-2022. The fatality rate for drivers and car crash partners by vehicle type and curb weight was calculated across these intervals to characterize changing self-protection and aggressivity over time. Results: Crash incompatibility between cars and SUVs/pickups improved between 2011-2016 and 2017-2022. Pickup trucks, which had previously killed the drivers of car crash partners at 2.5 times the rate of cars, were just 1.9 times more likely in 2017-2022. Similarly, SUVs over 5,000 lb reduced their car partner death rate from 1.9 times the rate of cars to just 1.2 times. We also found that additional curb weight conferred the greatest protective benefit to lighter vehicles while not accruing much additional risk to crash partners. The reverse was true for heavier vehicles, for which additional weight provided negligible extra protection but a substantial increase in crash partner risk. Conclusions: Crash incompatibility in the fleet has continued to improve in recent years, particularly among the heaviest pickups and SUVs. Although curb weight remains an important factor in driver protection, our data suggest that the benefit plateaus at 4,000 lb, with minimal incremental gains above this point. These findings suggest that vehicle design changes have contributed to safer outcomes and that mass reduction among the heaviest vehicles may further improve crash outcomes in the future without reducing the protectiveness of those vehicles.