During a police operation along the M1, police disguised as lorry drivers, were sent out to observe passing lorries and what causes most of them to start swerving.
After letting several lorries pass and glimpsing into their windows it seems that several drivers, especially those with foreign number plates, swerved the most and it wasn't the vodka! They were watching hardcore pornos whilst driving and the swerving was caused by (Well I'll leave that to your imagination).
The police then informed their colleagues waiting on a parking area and the guilty drivers were pulled in, some with sticky pants. Several of the drivers could not speak English, but after the police had searched their cabins it seems that they were stuffed full of Eastern Europe pornofilms; hardcore.
One driver who could speak several words of English attempted to explain why they watched pornos whilst driving, here his answer:
"ve have no time to stop, ve must drive day and night because our bosses demand it, so ve do it. Ve are 8 weeks away from ze wife so ve need a bit of relief and Eastern European pornos are perfect and because ve never stop, only for a sleep, ve have a "vank" (description altered for legal purposes) now and zen! Sorry for ze swerving when ve have ze climax!"
The police fined the drivers on the spot, confiscated the pornofilms (for later back at the station) and told them not to be such tossers because swerving can cause accidents!