The U.S. Postal Service has teamed up with a San Diego-based startup in order to test self-driving trucks that could be used to make deliveries.

The tests, which began on Tuesday, started in the southwestern U.S. states of Arizona, Texas and New Mexico. The trucks were provided by the California-based startup of Trusimple and will feature trucks traveling 1,000 miles between postal service offices in Dallas and Phoenix in order to see if it will make the postal service delivery system more efficient. The tests will take place over the next two weeks and will be done both during the day and at night.

"The work with Trusimple is our first initiative in autonomous long-haul transportation," USPS spokesperson Kim Frum said. "We are conducting research and testing as part of our efforts to operate a future class of vehicles which will incorporate new technology."

Trusimple hopes to bring the first self-driving semi-truck to the commercial market.

"It is exciting to think that before many people will ride a robo-taxi, their mail and packages may be carried in a self-driving truck," Dr. Xiaodi Hou, the CEO of Trusimple said.

The trucking industry is facing a massive shortage of manpower, and self-driving trucks could fill the gap. The American Trucking Association says that the trucking industry could be short some 175,000 drivers by 2024.