Americans are a mobile people. Their lives were changed by the invention of automobile (in the 1920s). It had great impact on the American economy. The auto industry created other industries such as tire manufacturing or gigantic highway program. Today, the automobile isn’t just a symbol of success, it’s a way of live. To have wheels means to be free. You can get a driver’s license at 16 in most states. Without getting out of your car you can buy fast food, mail a letter, get money from a bank, have film developed, see a movie and even attend a church service. On the road you can see for example: trucks with two or three trailers (called „Kings of the Road“), a lot of recreational vehicles (RVs) which goes on vacation. You can rent a limousine. There is a system of highways some of which have up to six lines. Each state has own traffic rules and regulations, but in all states you drive on the right. The speed limit in cities is usually 25 miles an hour (45 km/h), on the open road 55 miles (88 kph). A lot of cities support freeways more than public transportation. For example, Los Angeles has more cars than people. It causes terrible pollution and gridlocks. Drivers are supported to form car pools. It means that several people share ride to work. There are special lanes and reduction on toll charges for bridges in some cities. Bigger cities have undergrounds called subways. Some have overground railroad systems with street cars(for example BART, the Bay Area Rapid Transit System in San Francisco).Almost all American railroad tracks are used for freight traffic. There is Amtrak, passenger service that connects about 500 cities. Travelling by train is relaxing but it is fairly expensive. The cheapest way of transport in America is by bus. There is one national bus line called Greyhound that is in most cities. Tickets are open date meaning that you can travel any time you want. Because of the size of their country, Americans often use planes. There are over 60 national and regional airlines.