The big problem (aside from laziness and lack of economic incentive?) with recycling wood construction probably is the contamination with other construction materials. Asphalt paper, composition shingles and siding, plasterboard, wallpaper, paints, glues, etc. Separating the wood out to chip it is - or at least looks - rather expensive.

For community paving in my area at least, some asphalt is recycled. In some cases it can be done in place, with the old ripped up, rendered, and fed back through a heater to cast it back onto the original surface, with only supplemental additions of new material. It does take a fairly large project to justify the more specialized machinery ... and someone who knows how to do it and meet specifications.

John