It isn't "fear" of change, it is that political systems get captured by status quo interest groups that fight against change.
My guess is that comfort with this as a concept will be generational, as are lots of things. I like the idea a lot, but I also will miss driving. I doubt my daughter will miss driving in the slightest.
I don't think anybody will miss driving in traffic, but until there's some other way to experience the combined sense of control, shifting G-forces, and the world streaming by, manual driving on sparsely populated roads will always be desirable.
Further, I would submit that this is mostly due to the legislators themselves.
A trucker that doesn't have to 1) eat 2) sleep 3) experience fatigue -- this trucker is vastly superior. There is already a lot of analytics measuring truck performance, metrics which would make autonomous trucks very feasible.
Transport trucks spend hours on interstates between points going in relatively straight lines, at relatively low traffic times.
The trucking industry will be dead 5-10 years after robot trucks start appearing on the road.
EDIT: Sorry "trucking industry" should be in quotes, as yes, by this I mean the idea of people driving trucks, which is 90% of the "industry". The actual industry itself isn't going anywhere, agreed. My fault in the miscommunication.
That said, that "shift" is when it's going to be a really, really shitty time to be a truck driver, as the influx of people competing for fewer and fewer jobs is going to drive prices (wages) down into pits of dark despair.
As chollida1 points out, UPS/Fedex may not be allowed to lift the CLD requirement quite yet, but that will probably come in time.
I'm pretty sure the laws stipulate that a licensed driver must be in the drivers seat.
And then there's all the service stops which now offer food, etc for truckers. I expect few of them will successful transition to serve tourists exclusively.
The existing actors, however, might well be unable to drive that transition and they might consequently die and be replaced by other, new actors.
That's enough for a pair of drivers to keep the truck on the road continuously, and maybe almost enough to make it worthwhile to have just a single driver (so the cab owner doesn't have to split his profits with anyone). After gradually raising hours over the course of a few years, you can declare drivers optional. Owner-operators would still ride in the cab so they could handle pickup and delivery of trailers, but fleet owners might just hire drivers on the spot for things like that.
Edit: My (mis)understanding of trucking hours of service was based on a conversation with a truck drive a few months ago. Apparently, you can drive 14 hours continuously after taking 10 hours off. However, I think the point still stands that truck drivers will be less resistant to the introduction of robotic trucks if they perceive the change as a (at least short-term) benefit to them by increasing allowable driving time.
And fix the truck when it breaks down (if possible). And deal with problems when the wrong shipment goes to the wrong place, etc.
And protect the contents of the truck.
Driving is just one piece.