Before embarking on a summer road trip, drivers should exercise proper vehicle preparation, with tire care being especially important. 1) Visually inspect tire tread. 2) Use the "penny test" to determine the amount of tread left. If the tread does not cover Lincoln's head, you may need to replace the tire. 3) Use a pressure gauge to check tire pressure. 4) Inflate tires to the manufacturer-recommended pressure. (U.S. Air Force photo illustration by Senior Airman Jason J. Brown/Released)