You should be able to find power FETs that can be paralleled and are fast enough for your requirements. Bipolars would work as well, but with more drive current and series current-sharing resistors that aren't necessary with FETs.
The drive circuit would depend on your load current waveform...
MN DOT has put their inspection reports online accessible from
their bridge collapse website:
http://www.dot.state.mn.us/i35wbridge/index.html
These reports give you a fairly good overview of the design of the bridge, and contain some pictures to illustrate the inspection findings.
Here's...
