So the concern is the economy slowing down due to the large number of current truck drivers who are going to be out of jobs in the near future. I don't expect there to be a sudden drop.

First comes the autopilot trucks where they still need to be manned. Sure the drivers will likely take a hit in pay, they'll still have a job. Then comes the fully autonomous trucks, removing the drivers although. I see this being a gradual transition, not a cliff like the article mentions.

"Basically, the only real barrier to the immediate adoption of self-driven trucks is purely legal in nature, not technical or economic."

I feel like this is such a huge assumption considering any type of autonomous driving has not been seen use anywhere yet.