Your car breaking down far away from where you live is a real hassle and can even become a dangerous situation if you don't know what to do. There are a number of different things you can do if you find yourself in this predicament, depending on the specifics of the situation.
If you have access to a cell phone when your car breaks down, this will make everything a lot easier. Simply pull your car to the side of the road and turn on your hazard lights to warn other motorists that you are in need of assistance or to alert any passing police cars or emergency vehicles that your car has broken down. Use your cell phone to call a service that can tow your car, like the American Automobile Association (AAA). If you're not a member of AAA, call the nearest tow truck station or call a friend to do it for you and come pick you up. If none of these things work, call the police or local emergency services and tell them your location and situation.
If you do not have a cell phone or your cell phone is not working, leave your car locked with the hazards on and walk to the nearest gas station, assuming one is nearby. If one is not nearby or you don't know where the nearest gas station or garage may be located in relation to where you broke down, then try walking to a call box, which is installed every few miles along major American highways. The call box will connect with the local highway patrol and they will send a patrol car or a tow truck to come help you.
If there is no way to communicate with anyone and you are stranded in the middle of nowhere, then your only other solution is to flag down a passing motorist for help. This is not highly recommended, as it's dangerous to wave down a moving car and also not safe to tell strangers you're stranded and in need of assistance on the side of the road.
Most people on the road will be happy to help you out, though, by loaning you their cell phone for a call, calling from the nearest gas station or rest stop up ahead for you or even giving you a ride, if you feel comfortable doing so. This is obviously an option of last resort when you are in this situation.
