A study of numerous published rollover tests was conducted by reexamination of the original works, analysis of their data, and centralized compilation of their results. Instances were identified where the original reported results for trip speed were in error, requiring revision because the analysis technique employed extrapolation versus integration and lacked correction for offset errors that develop by placing the Global Positioning System (GPS) antenna away from the vehicle Center of Gravity (CG). An analysis was performed demonstrating revised results. In total, 81 dolly rollover crash tests, 24 naturally occurring rollover crash tests, and 102 reconstructed rollovers were identified. Of the 24 naturally occurring tests, 18 were steer-induced rollover tests. Distributions of the rollover drag factors are presented. The range of drag factors for all examined dolly rollovers was 0.38 g to 0.50 g with the upper and lower 15 percent statistically trimmed. The average drag factor for dolly rollovers was 0.44 g (standard deviation = 0.064) with a reported minimum of 0.31 g and a reported maximum of 0.61 g. After revisions, the range of drag factors for the set of naturally occurring rollovers was 0.39 g to 0.50 g with the upper and lower 15 percent statistically trimmed. The average drag factor for naturally occurring rollovers was 0.44 g (standard deviation = 0.063) with a reported minimum of 0.33 g and a reported maximum of 0.57 g. These results provide a more probable range of the drag factor for use in accident reconstruction compared to the often repeated assertion that rollover drag factors range between 0.4 g and 0.65 g.
