What they are telling you is the way to do it.
Here, I have done it real quick to show you:
That is a brush terrain, with a patch mesh road.
The road is 5x5 patch, with the middle row raised 8 and the 2nd rows raised 4. The brush is exactly on the terrain brush on the ends.
ok the zfighting is gone but the road doesnt look normal,it looks more like a mountain,its not that high but its very ugly,are u sure there isnt another way?