That sounds like the are using the plastic in place of the petroleum tar to glue/hold the aggregate together. That makes more sense than using the shredded plastic to replace the aggregate.
I don't know if India has the truck traffic/tonnage we do. I read that the engineers planning work on the interstates don't want to know what the car traffic is, just the trucks because they'll tear up the roads long before the cars do appreciable damage.
I wonder how the test road in Los Angeles is doing.?