[Checkyersix]

It's the only way to do it for extensive road networks. The only problem is that you'll often find funny triangles where an extra pixel got laid down, so you'll have to go through after and clean it up. Still much faster than doing it through FMB though. Curving the lines will just cause strange interconnected roads.

P.S. I recommend using an overlay of map_h to lay down roads. Most road networks take the lowest possible route, and it looks much better on a map than having roads go straight up over mountains, etc.