In context: The test represents the first time the USPS has contracted with an autonomous service provider for long-haul service. After the pilot, the Postal Service will evaluate and determine whether it wants to expand its partnership with TuSimple.

The United States Postal Service is conducting a pilot program in which letters and packages will be transported between two cities using custom Peterbilt trucks developed by self-driving startup TuSimple.

The pilot, which will run for about two weeks, will consist of five round trips between Phoenix and Dallas. The first haul is leaving Phoenix this morning according to Bloomberg.

Transportation is one of the biggest line items in the Postal Service’s budget. The USPS spends more than $4 billion on highway trucking services alone to help it deliver a staggering 484.8 million pieces of mail each day. Self-driving trucks could help the Postal Service save millions by eliminating human drivers and thus, skirting the hours of service regulations that govern how long humans can be on the road.

And it may come as a surprise to some that the Postal Service receives zero tax dollars to cover operating expenses, instead generating revenue from the sale of postage, products and services to fund its operations.

Lead image courtesy Greg K__ca via Shutterstock