What's with Autonomous Vehicles?

This actually looks like a reasonable application for autonomous trucks.
Volvo has struck an agreement with a Norwegian limestone mining company to provide hauling from the pit to the crusher. The route is 3 miles in length taking the trucks from the open pit quarry through two tunnels then out to the crusher site.

Volvo is being paid based on their ability to transport the material so they have a vested interest in the performance of their self-driving trucks ability to deliver material as promised. Testing is currently underway at the Brønnøy Kalk quarry with commercial operation of the trucks expected to begin in 2019.
A closed mining site along a defined route should be a relatively easy task for the autonomous trucks. Volvo will gather valuable data that can be applied to the continued development of autonomous solutions for the open road.
How long before you expect to see autonomous trucks on the roads in North America?