Architectural questions, by gum!

I'm working on a portfolio project which has turned into a very
city-of-the-future sort of design.  I started out with a simple little
light-rail station near De Anza college on Stevens Creek Blvd. in Silicon
Valley.  Then I got to wondering what it would take to take Stevens Creek
Boulevard, which seems to me the real commerical downtown of Silicon
Valley, and make a transit system work there.  My tentative answer involves
giving the whole street a second level with light rail and moving
sidewalks, sort of a 90's "el".  Realization of this project is unlikely,
to say the least, but I ought to get some good drawings out of it.  I
quickly ran into the limits of my structural knowledge & that's why I'm
writing this note.

Stevens Creek Blvd. is a major arterial, five to seven lanes.  Ideally, the
structure (which can & probably should be open) would span the whole thing
without columns impeding traffic flow.  I think that at most one line of
columns would be acceptable.  Is this even possible in a quake-safe manner?
Where would I go to look this up (exact details don't matter for my
purposes, but I do need fairly accurate descriptions of forms--I can read
engineering texts if I really have to).  Also, how fast do those moving
walkways I have seen in airports actually go?  (I don't think it matters
for my purposes, but I'd really like to know!)

R.