I don't think it is quite as dramatic as it may first seem, it was 56% of those stopped and tested, so they would have had to have been showing signs of drugs/alcohol to have been stopped. This would therefore be a very small % of all drivers.
You have very little to worry about compared to all the other dangers on the road.
To Complain or Not To Complain?
don't have a problem with under 16's having free bus travel,BUT

