The Brand Frequency Index
The Brand Frequency Index combines three components into a single composite score per brand, each expressed relative to a baseline of 100 representing the national average. The Frequency component divides a brand's share of the 56,011 vehicles involved in 2024 U.S. fatal crashes by its share of full year 2024 U.S. new vehicle sales (15.85 million units, CarPro/GoodCarBadCar). The Speeding component divides a brand's rate of speeding involvement within its own fatal crashes by the national average rate of 18.66%. The DUI component divides a brand's rate of driver BAC 0.08+ within its own fatal crashes by the national average rate of 29.28%. The three components are equally weighted and averaged, then multiplied by 100 for readability.