According to a survey by the Rubber Manufacturers Association (RMA), more than one in eight U.S. vehicles has bald tires – which can cause an increase in vehicle stopping distances and a higher susceptibility to hydroplaning.

More than 13 percent of U.S. vehicles have at least one bald tire – an increase from 10.4 percent recorded in a 2010 RMA survey. Further, a 2011 RMA phone survey of motorists found that 64 percent did not know how to check tire tread depth and 9 percent of respondents said they never check tire tread depth.

“Tire care is critical to keeping your vehicle road-ready,” said Dan Zielinski, RMA senior vice president. “Bald tires are dangerous and may lead to loss of vehicle control, particularly on wet roads. Checking tire tread is easy and inexpensive to do. All you need is a penny.”

RMA urges motorists to check tire pressure with a tire gauge, measure tread depth every month, and to get regular tire rotations and wheel alignments. In other words, RMA reminds drivers to “Be Tire Smart – Play Your PART,” which encompasses pressure, alignment, rotation and tread.

RMA recommends the “penny test” to check tire tread depth: insert a penny with Lincoln’s head upside-down into the tread of each tire. If the entire top of his head is visible, the tire is considered bald because it has less than one-sixteenth of an inch of tread depth.