Streets and roads are the segment of the environment where transportation is concentrated. Factories are the segment of the environment where manufacturing occurs. Farms are the segment where food is grown. etc. etc. etc.... Highways can be automated* just as factories are. Each segment of the environment can be specialized and automated too. Specialist agents would then operate in specialized environments.** (Someone can write a dystopian novel about a curious little forklift robot who escapes the confines of his factory for the freedom of the open road with the f.s.d. truck he met on the loading dock.)
* See my blog of 20 June 2025.
** I would have no idea of how to work on a farm and a farmer would have no idea of what to do in a physics laboratory.