Railroad

Railroad, land transportation system in which cars with flanged steel wheels run on tracks of two parallel steel rails. Railroads are economical in their use of energy because the rolling friction of wheel on rail is very low; however, costs of maintenance are high, so high traffic volume is needed. Costs, rising competition and overmanning led to the closure of many minor lines in the United States and Europe. Maintenance, signaling, and many other functions are now highly automated.

Railroads developed out of the small mining tracks or tramways built in the United Kingdom and Europe from the mid-16th century. They used gravity or horse power, and the cars generally ran on flanged rails or plateways. The first public freight railroad was the Surrey Iron Railway (1801). The modern era of mechanized traction began with Richard Trevithick's steam locomotive New Castle (1804). The first public railroad to use locomotives and to carry passengers was the English Stockton and Darlington Railway (1825). The boom began when the Liverpool and Manchester Railway opened in 1830 using George Stephenson's Rocket, a much superior and more reliable locomotive. In the 1880s track gauges were standardized at 4 ft 8 1/2 in (1.435 m), allowing various lines to use one another's rails. After ever-increasing development in the 2nd half of the 19th century, railroads began to decline in the 1920s because of competition from other forms of transportation, such as air travel, trucking, and passenger cars. The sharp increases in oil prices in the early 1970s appeared to give railroads a new lease on life; however, railroads were limited mostly to commuter lines, rather than to hauling freight. In the United States the national Amtrak system survived with the aid of federal subsidies.