People in cities need something similar. It would be hugely beneficial to have a bustling business district lined up on the left and right side of urban freeway crossings.
For example, see Minneapolis https://en.wikipedia.org/wiki/Minneapolis_Skyway_System
Crystal city VA on the other hand has an underground mall covering well over a mile including a subway stop. The upside is weather becomes irrelevant, but the downside it's a winding path making the surface faster and presumably it costs much more to build and maintain.
In SF there are a few spots where active use occurs underneath freeways. Also, in Taipei I saw a huge marketplace for jade and for flowers underneath freeways.
Freeways cause so many ill social and economic effects on neighborhoods, billions are wasted every year in the big cities on dead space. There should be a huge investment toward restoring the urban fabric and bringing out the full value of neighborhoods around these structures.
I was there in early fall, when it wasn't cold enough to make a difference, but we went through them for the novelty. Every time we emerged on the street, we were terribly disoriented.
But due to the currently high cost of construction projects, there is a lot of infrastructure that must be augmented rather than replaced.
https://goo.gl/maps/RfeVWuS2X5J2
A neighborhood torn apart 60 years ago....is still torn apart.
Do you know if the residential/commercial developments around the tunnel were built at the same time as the roadway? New transportation infrastructure is much easier to integrate into new urban developments, but it would be nice to see something done in existing communities.