You've reminded me of a medical study done by the NHS in Cardiff... Every girl who came into the hospital with a rape allegation was offered a blood test. They found that of the 100 or so who claimed that an intoxicant of some sort had been used (i.e. they'd been drugged), only 5 or so actually had any trace of such a drug in their system. This was well within the time that it takes for these chemicals to leave the system, so was pretty conclusive.
However, they found that 100% of the girls had large amounts of alcohol in the system... Usually because they'd drunk more than they realised (ever tried to do beer maths when you're THAT drunk?!)
It scares the c**p out of me when my little sister tells me she's going out for a night on the lash.
I agree. The most inappropriate use of speed I've ever seen is someone who (presumably) had broken down and parked on the carriageway of the A1 with no hazard lights on.