Tabletop Terrain has a tutorial on making flexible roads for your 15mm miniature wargames out of weed fabric and liquid nails.
roads
Making Ruined Roads from Vinyl/Lino Tiles
The Tabletop Terrain blog has a useful article on using vinyl/linoleum tiles to make roads appropriate for a combat zone or post-apocalypse setting.
Making Roads From Cork Tiles
The Wargames Table has a quick tutorial on making roads from cork tiles.
Making Roads For 15mm Wargames
Here’s a tutorial for making roads for your 15mm wargames.
The principal ingredient in these roads is vinyl composite flooring.