Hazards of tire aging

Human factors/ergonomics (HF/E) researchers at North Carolina State University have found that vehicle owners may not be aware that older but relatively unused tires can fail and cause crashes.

The researchers will present their findings on Friday, October 20, during the HFES 50th Annual Meeting at the Hilton San Francisco Hotel. The meeting will be held October 16?20, 2006.

An estimated 6,000 vehicular crashes in the United States each year are caused by improper vehicle maintenance and defective tires. Since the Firestone-Ford recall of defective tires in the late 1990s, U.S. lawmakers have taken action to improve tire safety. Congress enacted the TREAD Act, which requires a system for early warnings, tire pressure monitoring, tire safety standards, and consumer reimbursement. To date, the Act has not been fully implemented, and research on whether its provisions would be effective in enhancing safety has not received much attention.

Although many people are aware that tread wear and improper air pressure can be dangerous, this study of 227 individuals showed that very few of them cited tire aging as a potential problem. This is partly because information on tire aging has not been widely disseminated in the United States, until manufacturers recently began to include it in owner's manuals.

Some of the contributors to tire aging include exposure to ozone and heat and limited use, though consumers may not be aware of this. Complicating the matter is the fact that visual cues of aged tires are difficult to detect because, unlike worn tread or under- or overinflation, the aging process involves a slow degradation of the tire rubber, often from inside the tire.

The researchers conclude that warnings about tire aging need to be improved through, for example, clearly stating the manufacture date of the tires, explaining the factors that affect tire degradation, and distributing safety literature through tire and vehicle sellers, the press, and the Internet.

http://www.hfes.org