CITA webinar “The impact of safety inspection in the US vehicle fleet”
In its new webinar ( 1 March 2022), CITA invited Mr. H. Scott Matthews – principal at Avenue C Advisors and former professor in the Department of Civil and Environmental Engineering at Carnegie Mellon University – to present the results of the study “The impact of periodic Passenger road accident vehicle safety inspection programs in the U.S.A.” This research study, led by Prithvi S. Acharya, Laila AitBihiOuali, Daniel J. Graham and H. Scott Matthews himself, and partially supported by CITA, is a perfect example of how vehicle inspection is crucial to road safety and saving lives.
Considering that about 6.5 million roadway accidents occur in the United States each year, costing upwards of $240 billion, and causing over 30,000 fatalities, the U.S. Centers for Disease Control and Prevention (CDC) list motor accidents as a leading cause of adult mortality in the United States.
Presently, 15 U.S. states require passenger vehicles to undergo periodic safety inspections. Past studies estimating the effectiveness of these safety inspection and maintenance programs (I/M programs) in their stated aim of mitigating road accidents and fatalities have tended to rely on outdated data-sets, or to focus on specific geographic regions. Since inspection program effectiveness continues to be deliberated in legislative bodies across the country, this paper aims to present a replicable and data-driven quantification of the effects of I/M programs on road fatalities, applying the largest available data-set, covering all 50 U.S. states over a 44-year period.
This study presents strong evidence that jurisdictions experience lower roadway fatality rates due to the presence of an active safety I/M program for passenger vehicles. Panel data regressions showed a negative correlation between the presence of state I/M programs, and the fleet-size-adjusted roadway fatality rate. Fixed effects (FE) estimates suggest that states with I/M programs had 2.8% fewer roadway fatalities per 100,000 registered passenger vehicles (90% CI: 0% to 5.6%) nationwide, based on data from 1975–2018. A two-stage least-squares (2SLS) specification is also presented, which not only supports this finding, but also implies a causal relationship between the presence of I/M programs, and lower road fatality rates.