Create interesting roads (GIMP)

[holyhalo]

This is the current world of Kalyssia, after many re-imaginations, and it is finally populated in the general areas. Some places still need development however so there will be more populated islands as well. The problem I have now is that I can't seem to find a good way of depicting the roads. I'm not a fan of the white and black stripes some people use and I was hoping for something that seemed realistic. How would I go about it and is there a good or interesting way of creating roads? I've gone through most of the tutorials in GIMP but none of them feel right for this map. while the bossman is happy with the map as it is I feel as though the roads are too... Paint-y, no offense. They lack the air of professionalism I'm trying to keep.