Sign for the back of all trucks using UK roads will read as below:
“If you are going 70mph and you can read this 50mph sign, then your stopping distance is 40 metres further than it would be if you were travelling on a train from Glasgow to Edinburgh at 10am. If you were to take the bus to Edinburgh, you would save £27.30 and but the bus only travels at 11am and at an average speed of 40mph, and if the car behind the coach was travelling at 70mph and there was an accident, the stopping distance of the train would be unaffected – unless the accident was on a level-crossing and the coach hit the train, which would be horrific and we don’t want to even this about that. Basically, stick to the speed limit, or cycle, or take a plane, or a boat, but not a cruise in Italy, where the boat is likely to get hit by any of the following: another boat, plane, coach, car, heron, fish (not very dangerous), an island, Italy, water (again, likely, but not too dangerous), a drunken fellow passenger (that’s you getting hit, not the boat), a hefty bill (which is part of a large duck).”
The sign is still in consultation and there are likely to be a number of revisions.