If we are even thinking about digging a big hole in the ground for the Viaduct, why not just knock it down and instead bury I-5 instead?
The Real Estate that would be gained would be nicer. The mess that I-5 creates in the city would be gone, and the ambient noise in the city would go down by some big factor.
Why bother with the Viaduct, lets bury I-5 instead!
I also want a Monorail for Christmas...
...and a cupcake.