[mandrill7]

I have started making roads on a separate layer. I convert the map_t.tga into a psd file first, add a layer for the roads to be drawn on, then add another underlayer which shows the roads themselves as taken from whatever your source is (usually Google maps).

Then you can easily trace the roads with a pen tool.

If you use Paint Shop Pro, you can much more easily avoid the funny triangles by using the key while clicking with the pen tool. This way, two click-points are connected in a straight line automatically. Naturally for curving roads this necessitates lots of clicking, but it's still easier than drawing by hand.

Afterwards the psd is converted in GIMP to the suitable type of tga file.

I am however still trying to figure out how to clean up the triangles. How is that done?

Merci beaucoup! Those are some great ideas!!