A railroad car float or rail barge is an unpowered barge with rail tracks mounted on its deck. It is used to move railroad cars across water obstacles, or to locations they could not otherwise go, and is pushed by a towboat or towed by a tugboat. As such, the car float is a specialised form of the train ferry.

Beginning in the 1870s, the Baltimore and Ohio Railroad (B&O) operated a carfloat across the Potomac River, just south of Washington, D.C., between Shepherds Landing on the east shore, and Alexandria, Virginia on the west. The ferry operation ended in 1906. (See Capital Subdivision.)

The B&O operated a carfloat across the Baltimore Inner Harbor until the mid-1890s. It connected trains from Philadelphia to Washington, D.C. and points to the west. The operation was discontinued after the opening of the Baltimore Belt Line in 1895.

New York Harbor was especially rife with carfloat operations until the post-World War II expansion of trucking.

These carfloats operated between the Class 1 railroads termini on the west bank of Hudson River (New Jersey) and the numerous online and offline terminals located in Brooklyn, Queens, Staten Island, Bronx & Manhattan. Class 1 railroads in the New York Harbor area providing carfloat services were:

An automobile, autocar, motor car or car is a wheeled motor vehicle used for transporting passengers, which also carries its own engine or motor. Most definitions of the term specify that automobiles are designed to run primarily on roads, to have seating for one to eight people, to typically have four wheels, and to be constructed principally for the transport of people rather than goods.

The term motorcar has also been used in the context of electrified rail systems to denote a car which functions as a small locomotive but also provides space for passengers and baggage. These locomotive cars were often used on suburban routes by both interurban and intercity railroad systems.

There are approximately 600 million passenger cars worldwide (roughly one car per eleven people). Around the world, there were about 806 million cars and light trucks on the road in 2007; the engines of these burn over a billion cubic meters (260 billion US gallons) of petrol/gasoline and diesel fuel yearly. The numbers are increasing rapidly, especially in China and India.

Float or floating may refer to: