Looking at the construction photos I was impressed by how much viaduct there is, way more than flyovers, and just how butt ugly. No wonder the affluent folk of the Peninsula told PB to take a hike when those guys wanted to build elevateds thru the toney burgs of Silicon Valley. PB's Valley viaducts look like a half-height Embarcadero Freeway. Way blighty.

That's when it came to me why not turn them into an ultra high-speed tollway. Just 2 lanes but no trucks and not many on and off ramps. IIRC the Pennsylvania Turnpike was partly built on a failed RR ROW.

I dunno if these viaducts are to be decked all the way across like a highway or if there are spaces. Strength of the structure would be no issue. You can put parking for homeless campers, RV's, tents underneath. Solar panels above where the catenary would be.

Put Elon on the case.