What is the definition of a turnpike?

A turnpike is a road for which a fee is charged to travellers for use, in order to recoup the costs of construction and maintenance. Typically, a turnpike is a privately owned road, often built by a private company. They first developed in the 17th century in England and were also used in the United States. Turnpikes were also called toll roads, as they charged a toll to motorists for passage.