Asphalt/Concrete

Since the air-dry clay that I attempted to use to model asphalt cracked while curing, I'm looking for other ideas for materials I can use to model asphalt roads. Some people use Woodland Scenics Smooth-It, but I want to avoid anything and everything that starts out as a messy, ooey gooey substance that has to be sanded after drying/hardening (so no drywall joint materials, please). I've used messy stuff before and that's the last thing I want to do again. The asphalt material needs to be something that I can slope up and down for crossings. My foam roadbed is 1/4" thick and my track is HO code 100. I will consider any non-ooey gooey material & method. If all else fails, I may have to revert back to ooey gooeiness, although I certainly hope not.

 

What about a thin foam core board? Cut it to width & length, gently bend it to create any desired "cracks", paint it grey, then darker streaks for the tire wear areas, then a light AI wash.

 

I think I'm gonna try scrap shingles first. Besides, outside of laying real asphalt, that idea seems to be the most prototypical, especially these days.
http://www3.epa.gov/epawaste/conserve/imr/cdm/pubs/roof_br.pdf
Thanks for all the suggestions. I really appreciate all of the ideas.

 

I haven't glued anything down yet, but I think I've just found my preferred material and method for modeling asphalt roads. My parents had a few extra shingles left over from when they had a new roof put on their house. I used a 24" x 15" metal square and a hobby knife to trim them down as desired.