Quote: "can this script be used to prevent the terrain overlapping roads? "
If using any entity that has this line in the .fpe I would raise/lower the entity just a little so it locks to this height, any you place thereafter should either raise or cut into the terrain.
If you drop the entity it will revert to terrain height again but you could always remove one already placed and use the terrain beneath to get that height lock back again, not perfect but better than nothing at this point in time
A funny thing happened on the way to the forum...