Safe driving depends on regular tire maintenance It's crucial to keep tires in top shape. Learn how to maintain them and when to replace tires. Read the full description of the infographic Tread Depth and Tire Safety Your safety on the road rides on regular tire maintenance - literally. At 70 MPH, balding tires can increase average stopping distance by 184 feet on wet roads. (That's 4.5 school bus lengths.) At half-tread, resistance to hydroplaning DROPs 8%. Unfortunately, Having worn tires is a common problem: Of 11,500 vehicles studied: Nearly 50 percent had at least one tire with half-worn tread. Nearly 10 percent had at least one bald tire. If your car's tires are worn or balding, it's time for new ones. Here are three simple ways to check tire treads regularly: 1: Measure it out. On New Tires: The treads will measure 10/32 of an inch. Worn tires: 4/32 of an inch Bald tires: 2/32 or an inch 2: Grab a coin. Place a penny or a quarter upside down in the tread. Penny: If tires are new: Lincoln's eyes will be covered. Worn: The top of Lincoln's head will be covered. Bald: Lincoln's head will be fully visible. Quarter: New: Part of Washington's head will be covered. Worn: The tread will just touch the top of Washington's head. Bald: The tread will only reach the lettering. 3: Use your senses. Worn or balding tires can have: Visible wear bars Even appearance with outside tread raised sections on tread grooves smooth sections Other important tire maintenance These routine tasks will also help keep your tires in top shape: Check Pressure. Use a tire pressure gauge to measure at least once a month. Reference your car's owner's manual for the recommended level. Balance and rotate. On average, visit a professional every 5,000 to 8,000 miles. Align. As a rule of thumb, have a professional align tires every 6,000 miles or six months, whichever comes first.