In some places in Arizona, they already have autonomous self-driving vehicles (in pre-tested areas like certain neighborhoods) for Walmart delivery and eventually for UPS:
Waymo to move packages for UPS in Arizona this quarter - Business Insider
Waymo launched Waymo One, the first commercial autonomous ride-hailing service in the US, in parts of Arizona in 2018. Last year, the company began removing safety drivers from some of the vehicles used in the service. The company is now seen by many experts as the leader in the autonomous-vehicle industry.
Waymo to move packages for UPS in Arizona this quarter - Business Insider
Waymo launched Waymo One, the first commercial autonomous ride-hailing service in the US, in parts of Arizona in 2018. Last year, the company began removing safety drivers from some of the vehicles used in the service. The company is now seen by many experts as the leader in the autonomous-vehicle industry.