The video is a little confusing because at the start, the founder says that the plastics replace a percentage of the bitumen (so act as a binding agent). But at the 3:00 mark one of the workers says that the plastics are mixed the identical way as "any additions to a bitumen product". So that would imply that the plastics are being used as a filler. That would still be a great way to use waste plastic, but it's hardly a "plastic road". It's asphalt, just with a different mix of filler and hopefully a slightly smaller percentage of bitumen.