To me the trees in the background are a little big. The water in your creek looks odd. Have you tried any of the water presets, a few ripples, a little reflection. One way to do a road is to duplicate the terrain and then in the terrain editor drop the height of everything that is not the road. Then move the terrain a tiny bit up. Apply a suitable texture and you should get a raised road. The hard part is sorting out where the bridge is located in the terrain so that it lines up correctly.