It’s Tire Safety Week! Is There Anything to Celebrate?

In April, materials scientist John Baldwin bluntly schooled insiders at the annual Tire Industry Conference about things the rubber industry has known for decades from its own internal research. He pointed out that relying on tire tread depth to determine the viability of a tire is a bit of a crapshoot:

“In the tire industry, a lot of decisions are based on tread depth,” he said. “But what is the significance of tread depth? There is uneven wear on damn near every tire.”

He took note of the unsafe practice of rotating unused, but old spares onto vehicles:

“The average full-sized spare tire is nine years old,” he said. “You can tell your tire store to take that perfectly good spare tire and put it on your car. But if you’re in Yuma or Miami, do you really want that nine-year-old spare going on? “Meanwhile, the average mini-spare is 12 years old. That means you’re screwed.”

And he took exception to what he calls the Rubber Manufacturers Association’s (RMA) mischaracterization of his tire aging research for Ford Motor Company.

John Baldwin, a former 3M polymer chemist, was hired by Ford to help them analyze the root cause of tire failure-related Explorer rollovers. His published tire aging research formed, in part, the basis for the National Highway Traffic Safety Administration’s own oven-aging tire tests. It has been 12 years since the spate of tread separation-related rollover deaths gripped the news media, Congress and the public, spawning the Transportation Recall Enhancement and Accountability (TREAD) Act and a multi-year research program at NHTSA. The agency has developed and validated an artificial aging test. Automakers and some tiremakers have issued technical service bulletins warning about the dangers.

And yet, today, tire techs are still rotating aged, unused spares into service; you can purchase very old “new” tires at big box retailers; used car dealers sell older vehicles with old tires, and the consumer is none the wiser.

Cpt. James Gore, the father of a Nacogdoches 19-year-old woman who died in a rollover crash in June, says that before the left rear nine-year-old tire of Rebecca Gore’s 1998 Ranger suffered a tread separation, he “did not have a clue” about the age of the tires on the pick-up truck they bought in 2010, and did not think to ask.

“I had no idea about a DOT number; I had no idea what tire age was,” Gore says.

Rulemaking that would require a tire aging test has stalled out. Roderick Koehler, of the American Center for Van and Tire Safety, got the same sort of abrupt and horrible education as James Gore in July 2007, when his 10-year-old granddaughter Alexis James died in a 15-passenger van rollover crash. The van was carrying James’s softball team, when the 13-year-old left rear tire experienced a catastrophic failure. Koehler and his son-in-law Patrick James have been lobbying NHTSA for five years “to finish the work,” he says.

“NHTSA, when you meet them, they treat you respectfully. But they either flat-out lie or promise things they are unable to deliver,” Koehler says. “We’ve wasted enough time. Either aging is real or aging is not real and if it’s real, then it’s time to issue some guidelines.”

This week, the RMA is celebrating its 11th annual Tire Safety Week by lamenting, that “U.S. consumers’ knowledge of proper tire maintenance continues to be lacking and that its most recent survey showed only 15 percent of U.S. drivers knew how to check tire pressures properly,” according to a press release. But if these examples show anything, it’s that consumers know even less on the issue of tire age degradation.

“The issue is real simple,” says Sean Kane, president of SRS Inc. and a longtime advocate on tire safety. “The science on thermo-oxidative aging has been settled a long time ago. We’ve had warnings from the tire industry. We’ve had warnings from the auto industry. But no one is making any serious effort to move this into the tire shop and to the consumer level. At a minimum, what’s needed is a good training program, consumer awareness and a non-coded date of manufacture instead of the date coding that is mixed into the DOT number. Without that we will continue to see tires with good tread find their way back onto vehicles regardless of age – and we know this leads to deaths and injuries.”

And the real irony of Baldwin’s salty lecture at the tire conference? Ford, which sponsored and published so much research on tire aging, doesn’t appear to educate its own dealerships, service writers or service technicians about tire age.

With the exception of warning language added to its vehicle owner’s manuals and the Ford Motor Company website in 2005, the automaker that dragged the industry secrets out of the shadow, Ford apparently has not issued technical service bulletins, or service information, or included information about the hazards of tire age in Ford technician training materials, in the curricula at technical schools offering Ford affiliated programs or in communications with Ford dealership service writers.

SRS’s own informal surveys indicate that the people who sell and service tires are shockingly ignorant about tire age, how they age, the effects of tire aging, or even the recommendations of their own companies.

The numbers continue to show that motorists are paying for the RMA’s refusal to acknowledge the age factor in injuries and deaths. In 2008, SRS submitted to the tire aging docket a spreadsheet containing a list of 159 incidents in which tires older than six years experienced tread/belt separations—most resulting in loss-of-control crashes. These incidents caused 128 fatalities and 168 injuries. Our most recent incident count which will be submitted to the NHTSA’s docket today is 252, representing 223 fatalities and 300 injuries. This represents only a small fraction of the true incidence rate, because it is composed of crashes that resulted in civil litigation. There are no public data sources that capture tire age and failures.  In its 2007 Research Report to Congress on Tire Aging, the agency only noted 400 fatalities from 1994 to 2004, annually, that “may be attributed to tire failures of all types.”

Tire aging is caused by the thermo-oxidative degradation of the internal rubber that bonds the tires belts together that occurs over time, and is accelerated by heat, regardless of tire use. Once a tire is put into service the mechanical forces cause crack propagation beginning at the high-stress internal belt-edge area. Preventing the internal cracks from expanding to a tread separation, before the tread wears out, is critical. With age and heat, the materials become less elastic and less capable of preventing this crack propagation. The tire industry has been studying and addressing these issues for decades and has mitigated the problem through design, including anti-oxidants, reduced air permeation and more robust belt edge construction. However, at the same time, tread life has gone up significantly, exposing tires to longer in-service periods. NHTSA has reported that “the average tread life of a passenger car tire in the U.S. was approximately 44,700 miles in 2004, which represent[ed] an 86% increase from an approximate 24,000 miles in 1973.” That, combined with long storage, and inflation and use in warm climates, increase the chances of catastrophic tread-belt separation.

[flashvideo file=video/Tire_Aging_Demonstration.flv image=”video/TireAgePreview.jpg” /]

In the last few years, a number of tiremakers have also acknowledged tire aging, issuing Technical Bulletins specifying that all tires should be removed after 10 years regardless of the remaining tread depth. The bulletins also advise consumers to have their tires inspected annually once a tire reaches 5 years old. Most vehicle manufacturers have taken a stricter approach, recommending tire replacement after six years, regardless of tread depth and several tire makers advise owners to defer to the vehicle manufacturers recommendations, effectively making the 6-year recommendation the most prevalent.

The RMA, like tobacco lobbyists insisting that cigarette smoking doesn’t cause cancer, stands alone in insisting that age is irrelevant.

After a Promising Start, NHTSA Efforts at a Standstill; Rules Still Don’t Help Consumers

The Transportation Recall Enhancement Accountability and Documentation (TREAD) Act of 2000 required NHTSA to improve tire labeling to help consumers identify tires in the event of a recall. In June 2004, the agency adopted a Final Rule that required the TIN (Tire Identification Number – aka DOT number) be molded on the intended outboard side of the tire to give consumers easy physical access to the TIN. Manufacturers also had the option of molding a partial TIN, minus the date code, on the other side of the tire. NHTSA set the compliance date at September 1, 2009, and declined to change the date code to a readily recognized format using the month, day and year.

In November 2004, SRS petitioned NHTSA to initiate rulemaking to require a non-coded date of manufacture molded into tire sidewalls. The petition requested that tire labeling rulemaking be separated from the tire performance standards for expediency. We argued that changing the DOT from the obscure week and year representation to something that was immediately accessible to the average person wouldn’t conflict with other possible tire aging requirements. But, the agency decided to lump this petition into the tire performance rulemaking and indicated it would be considered at some future date.

NHTSA first published its tire aging proposal in 2003, suggesting several potential methods to artificially age a tire and test it. The industry opposition was strong. The agency, which had little experience in tire testing and no data, looked to industry for technical assistance. But, the tire industry mostly denied that an aging effect existed, despite the material science and its own internal testing. NHTSA’s efforts, however, got a boost from Ford Motor Company, whose research – motivated by a desire to blame the Bridgestone-Firestone Wilderness ATX tires in the rollover deaths, instead of the poor stability of the Explorers. Ford published its research and test methods, and began, in 2005, to publish a six-year tire safety warning in their vehicle owner’s manuals.  And it took SRS’s research to show NHTSA that the industry had a much deeper and longstanding knowledge and concern about tire aging.  In a series of submissions beginning in 2003, SRS cited studies and warnings from tire and automakers from around the globe – many of which predated their submissions to NHTSA claiming tire aging wasn’t an issue. (See SRS Tire Aging advocacy)

Over the next four years, NHTSA’s testing and research established a good artificial aging test protocol, followed by a road-wheel performance evaluation.

But NHTSA’s research and development continues to gather dust on a shelf. In 2008, NHTSA’s Vehicle Safety Rulemaking and Research Priority Plan for 2009-2011 listed as a priority the development of a regulation to require an oven-aging test for tires prior to endurance testing, to help reduce tread separations. The agency had expected to come to a decision in 2010, but the deadline passed without agency action. The agency’s newest priority plan drops tire age rulemaking to nearly the bottom of the list, and now says that the agency will reach a decision this year on requiring an oven aging test before running a tire through the FMVSS 139 endurance test.

The best the agency has been able to muster has been a web page on and a mention of tire age as a hazard in a 2008 and 2011 consumer advisory. In 2011, the agency’s Tire Safety Week message alluded to the dangers of thermo-oxidation, urging “all motorists to inspect their tires for proper inflation and signs of tread wear and damage before driving in hot weather.”

“Motorists should also be aware that aging tires and hot weather can be a potentially deadly combination, as older tires are more susceptible to heat stress, especially if they are not properly inflated. Motorists should check the tire sidewall to see how old their tires are, and to check with the tire manufacturer or the vehicle owner’s manual for recommendations on how often to change tires,” the advisory said.

For consumers, the regulatory inactivity means that their vehicles are equipped with tires that have not been tested for their resistance to thermo-oxidation, a real issue for motorists in the south and southwest regions of the U.S. But even if they were, the average consumer could not easily read the date code, because the number is still too obscure and hard to locate.

State Efforts to Require Age Disclosure Fail to Advance

The tire industry has been successful at cutting off state legislation at the pass. Its most recent victory was in Maryland, where HB 729, Consumer Protection – Tire Age – Required Notice died in the General Assembly Economic Matters Committee. The bill would have required tire sellers and distributors to place a label on the tire displaying the month and year in which the tire was manufactured and a statement about tire age and tire deterioration. The tire seller would also have had to put the tire’s age on the receipt and have the customer sign a written disclosure about tire age. Customers would receive a copy of the disclosure, and the retailers would retain a copy of it for an unspecified amount of time. The penalty for violating the statute would be not more than $500. The RMA opposed the bill, and used the Tire Industry Association to rally tire-sellers against the legislation at a February hearing.

Three years ago, a similar bill in California was withdrawn at the request of its sponsors. Although AB 496 passed the Assembly Floor by a vote of 49-29, the bill’s sponsors did not have the votes to get it out of the Senate Business, Professions & Economic Development Committee.

It’s Tire Safety Week and the RMA may celebrate its own success at hanging on to the tire age status quo, even as it bemoans consumers’ ignorance.

James Gore is mourning the loss of his daughter and mounting his own, small public awareness campaign.

“I trying to do everything I can so that other people don’t have to deal with what I’m dealing with right now.”