[zdragnar]

Put them above the road and tall trucks can't go through anymore. Plus, the support structures needed suddenly become obstacles for cars to hit when making emergency maneuvers or drivers lose control, and now you've got tons of glass shards, electrified wires and steel supports falling down onto the freeway.

Under the road is literally the only option, and it's a terrible option at that. Rooftops - or better yet, former farm fields- are always going to be cheaper and more efficient.

[atq2119]

There's a standard maximum height for vehicles that is taken into account for freeway bridges, so your first argument is nonsense.

The rest still stands, of course. If you absolutely do want to put solar panels in the same place as cars, starting with parking lots is clearly a better idea. Fewer problems with high speed collisions, the electricity is generated closer to where it's needed, and people will be thankful for having parking in the shade. (Still more expensive than putting panels on a roof or field of course.)

[zdragnar]

"Nonsense" would only apply if practice were as good as theory; a very very brief Google search will net plenty of results for freeway overpasses and pedestrian bridges being hit. One example:

https://www.cbs58.com/news/truck-wedged-under-bridge-shuts-d...

[Can_Not]

This isn't really a criticism of the core idea to just say "what if somebody built it stupidly low", traffic lights have been fine my entire life and maybe some highways will have to be skipped or doubled for NASA/ military purposes.