Trucks and cars are different. They've been running automated big rigs between Dallas, Houston, San Antonio, and El Paso for a few years now.
Given the significant weight and danger of death for other drivers, it'll be years until legislators allow their "safety drivers" to be eliminated from the equation. This makes the AI system more akin to enhanced cruise control than robotic trucking.
Here's one article about Volvo:
"Companies such as IKEA, UPS and FedEx have begun using autonomous trucks to make long haul trips across Texas, most often along I-45 between Dallas and Houston. In 2017, the U.S. Department of Transportation designated Texas as one of that nation's 10 proving grounds for autonomous vehicle testing. And Texas lawmakers have encouraged autonomous-vehicle development by making sure traffic laws do not encumber the companies." https://www.houstonchronicle.com/business/retail/article/vol...