Gouging out all the cracks is one of those things that ended up being more labor intensive than I expected. In some places the cork tore out in chunks, and on a couple of the edges long strips peeled away. It didn't matter. I saved all the debris from the process and once all the cracks were dug out, I used it as rubble in the voids and in piles on the street. After all the rubble was in place and the glue set up, I used a filbert brush to paint the lines on the road with PVA.
After giving the roads a coat of watered down Delta black, I painted the lines with a second layer of straight PVA. The idea here is that the definition from two thin layers of PVA will serve to make the lines visible through the painting process without my having to constantly retrace them... Here's hoping. The final step before the roads are ready for drybrushing is to give all the rubble a coat of watered down Delta black mixed with PVA. This will serve to help the deposits of rubble not to erode as I drybrush over them.Two years ago I bought a pint each of Blue Grey Slate and Seal Grey. All my craters, rubble deposits, roads, etc. will share these two base colours to ensure that all my terrain is tied together. The roads first get heavy drybrush of Blue Slate Grey, then Seal Grey. The PVA did its work wonderfully: the rubble stayed and the road markings showed through wonderfully. After drybrushing I picked out the road markings with Space Wolves Grey and then Skull White. Everything then got a coat of black wash. Once the wash dried everything got one last drybrush of Seal Grey.
Now all that remains of the road construction is the cratered section.
Cheers,
CJ