Why no sleepers on UK trucks

i remember their being a flash in the pan clampdown on cabbing it around the busy parts adjacent to london ,scratchwood services ect when we all got turfed out the cabs at night with some power mad wooden top spouting the no sleeping in your cab rule with your bunk had to be more than so many inches away from the steering wheel ect,and assumed standing around in the carpark all night was more conductive to a good nights rest possibly somewhere around 1980.■■
his operation of disruption went somewhat haywire when we all just climbed back into someone elses cab .
there was a bit of verbal consisting of " you cant do that,thats not allowed,prove it,and ■■■■ off" thereafter they did and we all got a kip.
it only lasted a very short time possibly because it got them nowhere once word got around.