They'll get hit and sheared off by plows and over-size loads, or just by drunks or idiots still driving dumb cars.

I do not think people have a solid grasp of how many millions of miles of road would need to be technified for self-driving cars to be widely viable.

Most likely, it's going to be a niche thing, tightly restricted to certain places that can afford to build and maintain the infrastructure.

I, for one, already fail to grasp where we manage to get the funds required to clear and level the land and butter a fresh layer of asphalt on top of it regularly enough to build and maintain that many roads to begin with.

Don't know about the US, but most roads in Europe already have coded reflectors to aid identification of lane geometry. Roadside reflectors have become a standard feature even on small rural roads, they're just hollow plastic half-tubes with reflecting strips on them. Cheap to install, cheap to maintain.

https://duckduckgo.com/?q=road+reflectors&t=ffab&ia=images&i...

Sure, but in the sense that road signs or traffic lights are a wear item. They wouldn't be exposed to the real causes of damage to roads (at least in my area) - transport trucks and road plows. They would need to be replaced at 5-30 year intervals, rather than 4-12 month intervals.

Traffic lights seem to have a pretty long lifespan.