Self-driving truck technology company TuSimple Holdings is mapping new freight routes from Arizona to Florida with UPS and has achieved considerable fuel savings for the package delivery company even at highway speeds.

Since 2019, TuSimple has driven 160,000 miles of cargo for UPS North America Air Freight NAAF division as part of its supply chain business, delivering fuel savings of approximately 13% at speeds between 55 miles and 68 miles per hour. Routes for this UPS unit typically run between an airport and a UPS facility.

The company said it shares data from its operations with UPS, which owns a stake in the self-driving truck technology company.

According to data from the American Transportation Research Institute, fuels account for 24% of the cost per mile of heavy trucks, the most expensive item after driver wages and benefits, accounting for 42% of the cost.

TuSimple’s network began in Arizona and has since spread throughout the American Southeast, with one of its goals being to build a national autonomous U.S. freight network by 2024.