Self-driving trucks begin mail delivery test for U.S. Postal Service
Heather Somerville
Reuters
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.
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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.