Utah was one of the early pioneers in bridge moving, but here they use it for new freeway overpasses. They build the new bridge next to the site, then move it into place when it's ready. The road only shuts down for a few hours while they do it. I've seen it used on several bridges in the Salt Lake area. It was cool to see it used for an existing bridge.

>A bridge is being replaced in West Vancouver, about 10km from where I live. The old one was moved recently to make way for the new. Interesting time-lapse videos of the process (one looking west, the other looking east):
>
>http://www.th.gov.bc.ca/highwayprojects/Old_Capilano_Bridge/video/Capilano_Bridge_Move_East/index.html
>http://www.th.gov.bc.ca/highwayprojects/Old_Capilano_Bridge/video/Capilano_Bridge_Move_West/index.html