Urban Space Saving: Reducing Traffic with Raised Roadways and Shops

[LughGlas]

I am attempting to make a plan for the re-development of a residential and commercial area, in a medium sized city. One of the major issues in this redesign is traffic... there is simply way too much of it. It is not possible to reduce the traffic load, due to the fact that an interstate highway, intersects here, with a major state highway, and which both intersect (closely) with 5 other local avenues.

One way I have come up with to reduce traffic in the area into make one of those major avenues essentially a bridge, which bypasses the whole area to be developed. But in an area where space is at a premium, it is not practical to simply make the avenue a non-intersecting thruway. This is where my question comes in. Is it practicable to place a 5 lane road, on top of special structures, which would double as both supports for the raised roadway, and as commercial shops?

I believe the roadway would be about 15' above the surrounding ground. My main concerns are integrity and noise. Would there be enough room underneath this roadway for shops? Second, if the shops were placed under the roadway, how much noise would there be in the shops? Would it be like a non-stop freight train running above your head? Or would it be more like white noise?

Any thoughts?

 

[Bobbywhy]

LughGlas, Welcome to Physics Forums!

Instead of looking for a solution in a vacuum, why not examine how others have dealt with this? Whenever a question such as yours appears I always ask “Has this problem already been addressed elsewhere? The answer in this case is “Yes.” Many other cities throughout the world have faced similar congestion and built elevated highways. Learn from their mistakes and from their successes. Just for example, see what New York City, Shanghai, and Mumbai have done:

http://en.wikipedia.org/wiki/West_Side_Highway
http://en.wikipedia.org/wiki/Expressways_of_Shanghai
http://en.wikipedia.org/wiki/Sahar_Elevated_Access_Road

I always enjoyed shopping in Taipei, Taiwan under their elevated “Ring Road”.
And in Rio de Janeiro there is a remarkably effective system of the same scheme.

Cheers,
Bobbywhy