Even a new, properly inflated tire can blow out. Debris, potholes and other road hazards can contribute to tire failure, as can tire age, worn conditions and over- or under-inflation.
How do you know when you have a tire blowout? Telltale signs include a rhythmic thumping sound, sometimes accompanied by a tugging sensation through the steering wheel. If you experience either, remove your foot from the accelerator, indicate a lane change, and then, while maintaining a firm grip on the steering wheel and taking care not to brake abruptly, pull off the road to safety and turn on the emergency flashers. If possible, bring the car to rest on level ground, which will be helpful when the time comes to jack the car up and change the tire.