I think I have posted this before....and would really like to see it in the next release )

Basically, a road tool that let you just draw the spline-line path and the set width, and it will conform to the terrain/site contour (on the z-axis to be more specific). It then extrude the proper 3D road model/surface with curbs as specified...(while retaining the site terrain below)
Another one would be to have ability to extrude along the spline... I have been trying to make fence conform to terrain to no avail...