September 26, 2018
Safety Fact: 733 is the total motor vehicle traffic fatalities in 2016 in which a contributing factor was tire malfunction.
Safety Fiction: On average, 200 people die each year in tire-related crashes.
The National Highway Traffic Safety Administration happens to be the purveyors of both tidbits, and the discrepancy is not just a matter of facts, it’s a matter of rulemaking and a matter of mixed messaging.
For years, the agency clung to the lower figure, based on a suspect methodology, and used this figure to forego a rulemaking on tire age and to educate the public about tire safety. In December 2014, Randy Whitfield, of Quality Control Systems Corp presented a statistical analysis of tire crash data, challenging this particular agency statistic at the National Transportation Safety Board’s (NTSB) two-day Tire Safety Symposium in Washington, DC. The symposium gathered stakeholders to share information on tire age, the recall system, tire construction, technology and tire-related crash data with the NTSB. Co-authored by Alice Whitfield, the study criticizing NHTSA's tire-related fatality counts was commissioned by The Safety Institute.
And now, nearly four years later, NHTSA has apparently decided to revise its estimate of tire-involved crash fatalities to something more reality-like, and to publish it in at least one place on its website.
“Safety advocates and proponents of the scientific method who have been asking for accurate, tire-related crash statistics are going to have to come to terms with getting 'yes' for an answer,” says Randy Whitfield. “Why is this important? Now that we know these crashes aren’t going away, now that we know the tire aging problem may not have been resolved by existing regulations, what are we going to do about it? Why can’t we put an easy-to-find and easy-to-read date of manufacture on a tire's sidewall? Why is that too hard?”
There are several possible sources of tire-related crash information, including state accident reports, Early Warning Reports, the Fatality Analysis Reporting System, the National Motor Vehicle Crash Causation Study, and the National Automotive Sampling System/Crashworthiness Data System (NASS/CDS).
In 2014, NHTSA relied upon NASS/CDS data to show near-miraculous results of an upgrade of FMVSS 139. In a report released in May of that year, the agency said that its most recent analysis of tire-related crash data from 2007 through 2010 showed “a 35 percent reduction in tire crashes (17,019 to 11,047), a 50 percent reduction in fatalities (386 to 195) and a 42 percent reduction in injuries (11,005 to 6,361) when compared with annual averages from 1995 through 2006. The overall fatalities decreased by 20 percent between 2007 and 2010 (dropping from 41,059 to 32,885 fatalities), and overall police reported crashes decreased by 10 percent between 2007 and 2010 (dropping from 6,024,000 to 5,419,000).”
The agency attributed these decreases to requirements for tire pressure monitoring systems in new vehicles, along with “a more stringent FMVSS No. 139” that helped “create better-quality and safer tires.” It concluded: “At this time, the agency does not believe it is necessary for motor vehicle safety to add a tire aging requirement to its light vehicle tire standard.”
Safety Research & Strategies president Sean Kane, also the founder of The Safety Institute, said “I have no doubt that FMVSS 139 – which was the first real upgrade to the tire standards since its original promulgation decades earlier – improved tire robustness. But, tires are not impervious to age degradation and absent easily identified dates of manufacture and clear and accessible guidelines on service life, tire age-related failures will continue to cause death and injury particularly because old tires can look just like a new tires – it’s an invisible hazard.”
In his presentation before the NTSB, Whitfield demonstrated that NASS/CDS was a weak foundation on which to base any claims of tire-related crash trends. NASS/CDS is a probability sample of police reported tow-away crashes involving passenger cars, light trucks, and vans. Whitfield argued that the relatively small sample produced annual estimates that were based on very few actual crashes, resulting in unreliable estimates and trends that were more likely due to statistical noise rather than to true yearly difference. The NTSB also pointed out that the sample was heavily skewed geographically – the vast majority of the fatal tire-related crashes in NASS/CDS during the period 1995‒2012 were located in Arizona (41 of 64 fatal crashes).
In contrast, Whitfield said that FARS, as an actual census of all fatal crashes on public roads in the US which includes data about tire-related crash factors, provided a much more realistic view of tire crash trends.
The probability estimates that NASS/CDS produced didn’t come close to matching the FARS count, Whitfield argued. Nor did it reflect a basic tenant of the tire failures – that they are related to heat and climactic conditions and increase along with temperatures. NASS/CDS estimates did not show a seasonal pattern.
The NTSB’s October 2015 report agreed that a comparison of NASS/CDS to FARS data showed “the NASS/CDS data appear to underestimate the number of tire-related crashes, injuries, and fatalities. Additionally, for this particular factor, NASS/CDS did not provide a representative distribution of tire-related crashes across the United States.” The Board recommended that NHTSA go back and determine the actual level of crash risk associated with tire aging since the new FMVSS 138 and 139 came into effect; and “if it appears that the aging-related risk should be mitigated, develop and implement a plan to promote the tire-aging test protocol to reduce the risk. (H-15-33).”
In 2016, then-Administrator Mark Rosekind made a head-scratching reply. He told the NTSB that NHTSA had already done the analysis in 2014, and suggested that since the new requirements of FMVSS 138 and 139 came into effect in September 2007, and since manufacturers recommend that vehicle owners replace tires after 10 years, there wasn’t “a significant amount of crash data currently available with which to analyze FMVSS No. 139 compliant tires that have aged significantly past a manufacturer's suggested lifespan.”
So in 2016, NHTSA didn’t have enough data to determine if FMVSS 139 is effective, but two years earlier it had enough to show amazing results and to decide there was no need for a rulemaking. Okay, Mark.
The Safety Institute, which originally sponsored Whitfield’s statistical analysis of tire-related crash trends, has sent a letter to Acting NHTSA Administrator Deputy Administrator Heidi King to request that NHTSA fix that annual tire-related crash fatalities figures in its other educational materials to match the actual figures. (Read The Safety Institute's letter here.)
That would not be welcomed by the Tire Industry Association. In April 2014, its president Roy Littlefield sent a snippy letter to NHTSA declining to promote NHTSA’s In the Garage Infographic and educational video. (Read the Tire Industry Association's letter here.) While the TIA approved of NHTSA refraining from making any specific tire age recommendations, opting instead to urge consumers to have annual tire inspections, it took extreme umbrage at NHTSA downgrading its annual estimate of how many people die in tire-related crashes each year from 400 to 200:
“It is one thing to say that '400 people die every year as a result of tire failure due to improper inflation' and something completely different to just say any number of people die as the result of tire failures. The message as it stands tells consumers that tires are dangerous products because they kill hundreds of people each year. The actual number is inconsequential because it does not tell the whole story unless it is tied directly to the lack of maintenance. Nothing has changed since September of last year because lowering the number to 200 doesn’t make it any less misleading. Two hundred people die every year in tire-related crashes as a result of what?” he wrote.
So how many people die each year in tire-related crashes? 200? 400? 700? It’s hard to get a grip on reality when your agendas inform your figures, rather than the other way around.