Component Performance / Effectiveness Analyses

JP Research has undertaken field performance studies of various vehicle safety systems and components using state and federal crash data. For several vehicle components subject to NHTSA investigations, JP Research has performed statistical analyses using consumer-complaint data compiled by NHTSA, along with registration data compiled by R.L. Polk & Company, to address component failure rates.

JP Research has also studied warranty claims, test data, and production batches to determine whether there were any predictable failure issues; used warranty and insurance claims data to examine the effect of publicity and increased inspections on claims rates; quantified the effectiveness of various inspection procedures in reducing failure rates for vehicle components; and developed techniques to account for reporting biases influencing failure rates.

ABS Crash Performance Study

In 1996, JP Research led an examination of the effectiveness of anti-lock braking systems (ABS) in preventing accident and injury risk. Using state and FARS data, the study analyzed over 60,000 accidents involving vehicles with ABS under various road conditions and concluded that, while there was no measurable difference in fatal accident rates between ABS and non-ABS vehicles, ABS vehicles did show 9-11% reductions in overall crash rates, and ABS seemed especially effective in reducing the occurrence of multiple-vehicle crashes.

Results are published in “Accident Experience of Passenger Vehicles with Four Wheel Antilock Braking Systems,” in 40th Annual Proceedings of the Association for the Advancement of Automotive Medicine (AAAM).

Warranty / Claims Data Analyses

For a component manufacturer, JP Research performed statistical analyses (lognormal and nonparametric survival analyses) of warranty claims data to address current and future component performance. The analyses examined various production periods at the manufacturer’s plants that were associated with components with low and high “failure” rates.

The goals were to establish whether there were predictable patterns and to determine whether units produced at certain of these periods could result in high future “failure” rates based on exposure rates of calendar time or mileage.

Effectiveness of Auto Theft Deterrent Systems

A recent study conducted for the Alliance of Automobile Manufacturers evaluated the effectiveness of parts marking and factory-installed anti-theft devices as theft deterrent systems. JP Research used theft data from the FBI’s National Crime Information Center and detailed vehicle identification information (to identify makes/models equipped with parts marking and anti-theft devices) obtained from auto industry sources

The statistical analyses ranged from simple correlation analyses to development of Poisson log-linear models. Statistical analyses were performed to determine: 1) the effectiveness of parts marking, 2) the effectiveness of anti-theft devices, and 3) the relative effectiveness of anti-theft devices compared to parts marking. The analyses controlled for a number of confounding factors, and 24 vehicle model lines that went from parts marking to anti-theft devices were analyzed separately to determine the relative effectiveness of the two theft deterrent systems for the same vehicle model lines.

Results indicate anti-theft devices were consistently much more effective in reducing thefts (approximately 1.5 to 2 times) compared to parts marking. The final report was submitted to the Department of Justice Docket (regarding the Anti Car Theft Act of 1992) on April 24, 2006.