Well, there are many kinds of plastic, technically, this could be something new. But some places have been adding plastic to asphalt for a while now, it certainly is cheaper in the short/medium term. And who knows, maybe this has different properties from all the existing systems, but I doubt it. I think this is just reporting research findings on the existing systems.

Currently, where I've seen this done, when the road finally does need repair, you have a whole lot of heavy waste to deal with. I don't have exact numbers on hand for what the financial or environmental cost comparisons are, but I think anyone could infer that reusing 100% of the existing material, and adding an extra 20% in order to repave a road is probably going to be a more optimal option when compared to replacing it all and then dealing with a huge amount of waste.