I also suggest putting a peice of regular currogated cardboard under the road section. Before you glue down the road, take a hard object and impress into the cardboard some "ruts" and variations. Then when you glue down the latex street, press it down to conform to the cardboard and you get a very realistic older road that has settled a bit.
I also recomend using some quick setting wood glue, such as Titebond III. It gets tacky much faster than white glue, and holds the latex very well. PLUS its water resistant after it dries, so it wont disovlve on you from later washes.
You can use any paint you want on it. I airbrushed mine various shades of grey, then picked out some individual stones in other grey/tan/etc colors. The later overall washes, dusting, etc blends it all together.
dont forget to take some fine sand or something and work it inbetween the stones. A old road (even more than 6 months old) would have all the cracks filled with soil. Diluted white glue (add some rubbing alcohol to help it flow) works great to glue the sand in after you have added it.
The stuff is the best ive ever found for economical, well detailed, roads and stuff. Its just awesome!
below is an example of a small dio i used it on:
enjoy
Andy

