3D Terrain

Does anybody know a good way to do a terrain with streets and walkways. Here's the issue:

AutoCAD Civil Drawings, including
Contours, Roads, Walkways.

MAX Terrain makes a mesh

I cant project my roads on to my terrain without it being a NURBS object.

So...Is there a way to project a shape on to a non-NURBS surface?

Thanks

try using the comform object modifier on a mesh object with lots of segments, or you could use a spline (line)object and extrude it, then conform that to the ground terain.