All urban highways that are even the least bit sunken should be covered or tunneled 

More real estate

More parks

Less noise

More footpaths 

Etc

Etc

👨🏻‍🍳 Better cook than I look 👨🏻‍🍳 
🧪 Dada scientist 🧪 
📐 Student of design 📐 
👾 👾 👾 👾 👾 

 /ai-art

Or vertical wind harvesting turbines

For the non-sunken solar though I think something like this would do better given the modularity and improvability. Line or even cover with a non-structural tunnel of these. 

But huge fan of solar (and wind) everywhere

And if they're not sunken, solar roads should be in place.