Historically, anything that reduces cost of transporting goods has advanced extremely quickly. The best comparison, I think, is the shipping container.
It took about ten years for shipping containers to go from an invention nobody had heard of to one that was being used in every major seaport in the world and about another ten years for virtually all shipping used that method.
The New York docks for example, dramatically increased activity (as in, handled several times more cargo per day) while also reducing the workforce by two thirds. I think self driving trucks will do the same thing - companies/cities/highways that adopt AI will grow rapidly and any company/city/highway that doesn't support self driving trucks will suddenly stop being used almost entirely.
Shipping containers were not a simple transition. New ships and new docks had to be built to take advantage of it. A lot of new trucks and trains were also built. Just 20 years to replace nearly all the infrastructure in one of the biggest and most important industries in the world.