/// Notices all over the buses to tell people not to do it, keep feet off chairs, no bags on seats, and no litter, do they take any notice, do they hell. ///
And yet everyone obeys the 'No Smoking' rule, I wonder why?
perhaps because someone will batter them if they light up, the driver would most likely stop the bus if it's known someone is smoking, then the rest of the passengers will be irate.
The rule about not smoking in public (including on buses) is national and is real legislation that has been passed by parliament. They are enforcable by law, and failure to comply results in a very hefty fine.
Rules about not putting feet on seats, eating, being rowdy are bus (or rail) company rules. Not national law, not backed up by fines.
In short, the threat of a fine is why people (mostly) do not smoke on buses.