Self-driving trucks begin mail delivery test for U.S. Postal Service
Heather Somerville
Business News
May 21, 2019 / 5:08 AM

Originally Posted by article
San Diego-based startup TuSimple said its self-driving trucks will begin hauling mail between USPS facilities in Phoenix and Dallas to see how the nascent technology might improve delivery times and costs.
The pilot program involves five round trips, each totaling more than 2,100 miles (3,380 km) or around 45 hours of driving.

Here is a link to the San Diego-based startup TuSimple.