Evaluation of motorcycle antilock braking systems

June 2015

Objective: Previous studies have found lower crash rates for motorcycles equipped with antilock braking systems (ABS). Although prior studies controlled for a variety of personal factors related to motorcycle crashes, they did not control for the possibility that riders with similar demographics still can differ in the likelihood that they buy optional safety equipment and that this difference might be related to their crash likelihood. Specifically, motorcyclists who purchase ABS might be more likely to behave in a manner that makes them less likely to crash. The purpose of the current analysis was to examine the influence of individual crash risk on the frequency of insurance claims under collision coverage for ABS-equipped motorcycles. Auto collision claim histories were used as a proxy for the crash risk of individual riders, independent of the motorcycles they ride. Methods: Coverage and loss data on nearly 2 million motorcycles by their unique vehicle identification numbers (VIN) were supplied by 13 insurers for model years 2003-14. The VINs were used to determine the ABS status of each motorcycle. Demographic characteristics including gender, marital status, date of birth, zip code, and insurance company were used to match the riders of these motorcycles to their auto insurance histories. Riders without any auto insurance history were excluded. Regression analysis was used to quantify the effect of ABS while controlling for auto claim frequency and other covariates including rider age and gender, garaging state, and collision deductible. Results: Motorcycle riders with higher auto collision claim frequencies were associated with higher motorcycle collision claim frequencies. Riders with high auto claim frequencies (an average of more than two auto claims per 5 years insured) were associated with motorcycle claim frequencies that were 64 percent higher than those for riders with a history of zero auto claims. The percentage of motorcycles with ABS optionally equipped increased with the riders’ auto claim frequencies. After controlling for auto claim frequency, motorcycles equipped with optional ABS were associated with a 21 percent reduction in claim frequency compared with similar motorcycles without ABS. Further analysis indicated that the reduction in motorcycle claim frequency associated with motorcycles equipped with ABS did not vary significantly depending on the auto claim frequency of the rider. Discussion: Among motorcyclists with both auto and motorcycle collision insurance coverage, there was a strong relationship between motorcycle and auto claims experience. However, there was no evidence that safer riders, as measured by auto claim frequency, were more likely to purchase motorcycles with optional ABS. Rather, riders with higher auto claim frequencies were more likely to ride motorcycles with ABS. Most important, controlling for a rider’s auto claim frequency did not substantively change the observed ABS effect, and the 21 percent estimated reduction in motorcycle collision claim frequency was consistent with prior research. Conclusion: This analysis evaluated the real-world safety benefits of motorcycle ABS while also addressing the potential influence of self-selection by safer riders. Results indicate that all riders may be expected to benefit from ABS technology on their motorcycles. This study also confirms that auto crash risk is a reasonable proxy for a safety profile that may be applied to future research on other optional safety technologies.