There is also another possibility to make roads look good without them flickering, but it only really works on straight roads as it requires some math:
When I was working on the GTA mod I had the rather unpleasent duty of making a city (get the first pre-BETA here:
http://members.lycos.co.uk/ofpadved. Bothe the site and the island were never finished btw). Anyway I was trying to make the roads fit seemlessly.... and then I had an idea - each of my road parts was a certain length (20m I think) and you can actually set the exact coordinates in the Object placement window in WRPEdit. So what I did was, I placed a road part at say [1000, 1000, 0] and then the next road at [1000, 1020, 0]. that way they fit absolutely perfectly, as you will see if you DL the map. This may be of help when making roads for other islands - exept calculating the exact positions for curved roads would be far more complicated. But possible, nevertheless.
MadDogX