I know this is late in the posting, but it needs to be said.
MEP has conduit, at least in 2011 it does. What it needs now is conduit duct banks.
It needs the ability to create a duct bank family. My thought are it would work like drawing the cross section & extrude the duct bank along a path.
Please create a DUCT BANK tool.
Are the parallel conduit runs in 2012 what you are looking for?
Parallel conduits can be used but I also need to have them encased in concrete.
The concrete also contains rebar. The rebar that run perpendicular to the run can vary depending if run under vehicle pavement.
I've learned a lot since my original post. I've created a variable length family that I place in blocks. It works well with sections as well.