The United States Postal Service (USPS) has awarded autonomous-truck creator, TuSimple, a contract to conduct a 2-week pilot program of self-driving trucks starting on Tuesday, May 21, 2019. The self-driving truck startup reached “unicorn status” earlier this year with a $1 billion valuation.

This trial run will transport mail more than 1,000 miles each way between Phoenix and Dallas over the two week period and be used to gauge the affect self-driving trucks could have on delivery times and operational costs for the mail service. TuSimple will complete five round-trips, hauling USPS trailers from a distribution center in Phoenix to another in Dallas.

Each autonomous shipment will be accompanied by a safety engineer to ensure nothing goes wrong during the journey. TuSimple’s self-driving trucks are ranked as Level 4 autonomous, which means that they are capable of operating without the need for a human driver or monitor in certain conditions. Safety engineers will only be present during test runs and are not expected to be needed long term.

During the USPS pilot, the TuSimple trucks will autonomously navigate I-10, the southernmost cross-country interstate highway in the American Interstate Highway System. The I-10 is one of the busiest highways in the country and roughly 60% of all U.S. economic activity touches its pavement at some point.

TuSimple vehicles will also traverse the I-10 in the USPS pilot, indicating that road conditions are suitable for Level 4 autonomy. 60% of U.S. economic activity touches I-10 at some point, according to TuSimple’s press release announcing the contract. In addition to good operating conditions, the length of the route along with on OTD pressures makes it an ideal candidate for self-driving trucks to replace traditional, human-operated ones where drivers work in teams to relay shipments, often working overnights. These factors make it the ideal testing grounds for a long-haul pilot program.

“It is exciting to think that before many people will ride in a robo-taxi, their mail and packages may be carried in a self-driving truck,” said Xiaodi Hou, the founder, president and CTO of TuSimple.

TuSimple’s announcement comes after stalling news about autonomous trucks throughout the industry. Self-driving vehicle creators must battle challenges from regulations to different weather conditions nationwide before they can hope to begin selling to the public or government. TuSimple’s new contract with USPS to conduct a two-week pilot is seen as the next step in the process of making autonomous delivery a reality in the United States.