Ok im pretty sure my friend is talking a load of crap. However you can never be too sure so I would like to check it over with you guys.
His claim is; to hitchhike in the UK with a HGV driver, the hitchhiker needs to carry a “special” form which is disc shaped.
Apparently this form is used somehow to clock the mileage of the truck and speed.
Is this nonsense? I always assumed when you hitch a lift with a car driver or a lorry driver, they are just doing you a favour and nothing is monitored.
I’ve done a small amount of hitch-hiking in the UK and parts of Europe and I’ve never heard of such a rule, but then I was never picked up by a HGV. One of my trips was a sponsored expedition on behalf of a national charity. They were very careful to make sure we knew all the relevant laws and rules as well as safety tips and so on, so I’m sure they would have mentioned a rule like that if it was on the books.
Not a definitive answer, I know, but that’s as far as I know from my personal experience on the subject.
The disc being talked about is a tachograph - but it has nothing whatsoever to do with hitchiking, and your friend needs to stop and think before talking 
I think that some potential Hitch-hikers show this disk so as to let let truck drivers know they are fellow truck drivers and thus get a lift. You seem the same with car delivery drivers. In their case they wave those temporary trade number plates at drivers, hoping that a fellow delivery driver will give them a lift.
I meant to say " you see the same…" :smack:
Which friend? Gorst?
Rayne Man’s explanation seems rational. I don’t think commercial vehicles tend to stop for hitchhikers in the UK any more, as the insurance normally doesn’t cover unauthorised passengers. I’ve never seen hitchers waving tacho cards, but then I don’t hang out in truck stops as much as I used to. I see plenty of hitchers carrying trade number plates, on the lookout for fellow car dealers, so I could imagine a similar system, but with tacho cards, being adopted by the road haulage community.