>>1069415That depends on a number of factors though. If it's an elevated highway, you can make it a viaduct with commercial uses occupying the space under the highway. But this really only works when it's smack in the middle of an urban area. Doesn't really work in a more suburban area.
If it's a highway in a trench, it's even easier as that can just be capped over and be built on top of, or simply just build out the bridges that cross over the highway. Pic related is Columbus, Ohio and if the right of way was wider they could totally put a train in the median and hook up escalators and elevators up into the buildings sitting over the highway.
The ironic thing about this, there used to be a train station and rail line where that highway now exists. When they built that cap over it, its architecture was inspired by the station that once stood there many decades ago.
