HOUSTON -

The National Highway Transportation Safety Administration estimates that tire failure causes about 11,000 crashes a year.

The NHTSA has put together easy ways you can make sure your tires stay in good shape as the summer heats up.

Summer is peak season for family road trips, but NHTSA warns that hot weather and under-inflated tires are a dangerous combination.

If you don't already have a tire pressure gauge, buy one to keep in your car.

On the inside of your driver's side door, you'll see the manufacturer's recommended tire pressure for your vehicle.

Check your pressure once a month, because tires lose one pound per square inch every 30 days.

Proper tire pressure can also improve your gas mileage.

Next, monitor the tread on your tires.

Try the penny test; put a penny in the tread of your tires with Lincoln's head upside down facing you.

If you can see the top of Lincoln's head, you are ready for new tires.