-None of the Red areas should be an issue. I would recommend closing the game and retrying (possibly restart your phone). If that does not work, go into the map editor (the cross of the right had of your screen) and drag and drop a road into that location. let me know if that does not work.
-The blue areas are just textures added by the developer to add realism, you can place any item there.
-bonus note, you can place spikes directly on top of a road, it will be in a more heavily traveled area, and will blend in more.