laying roads (walls, tracks, moats etc)

A while back I was interested in how you might lay out a road.  I'd been looking at classic tile-based games like simcity and I wanted to get away from tiles.

If you lay out a path and the road takes a sweeping hermite spline then it feels just plain wrong.

I got much better results from treating each joint as a circle and joining up the tangents of adjacent joints.

I thought you can get very nice tiling of the road/train-track/whatever if you use a texture atlas where the tiles are arranged vertically, letting you use GL_REPEAT on the horizontal.  You then generate a quad strip without needing to divide long straights into too many quads whilst still having the option of a bit of variety and such.