WASHINGTON, March 21 (Xinhua) -- Latest data showed that the total mileage of U.S. drivers in 2018 surged to a record level of 3.225 trillion miles (5.16 trillion km), the Federal Highway Administration (FHWA) of the U.S. Department of Transportation said on Thursday.

　　The figure is 12.2 billion miles (19.52 billion km) more than the previous year and is over 3 trillion for the fifth year in a row, according to FHWA.

　　U.S. Transport Secretary Elaine Chao said the record high mileage was a sign of favorable economic conditions and gas prices.

　　"Record-setting vehicle-miles traveled reflects a robust economy, lower gas prices and is another reason to ensure that America's roads and bridges are well-maintained and modernized to improve safety," said Chao.

　　FHWA also said that demand for cargo and delivery services in the United States set new records as well. In 2017 and 2018, the U.S. saw more demand for freight than ever before.