Perhaps, in the end, a higher price will be a far more effective warning sticker than anything America's surgeon-general could ever dream up.

ECONOMIST: Letters

That said, you cannot blame them for sticking with a winning formula, even if it should come with a free sticker warning: 'for use at coffee mornings and corporate dinner parties only'.

BBC: By the BBC's Chris Charles

This photo shows a warning which one of our crew cars received (the driver actually had a 'sticker' allowing him in the lane - but that's another story).

BBC: Is TfL Games Lane 'warnings not fines' tactic working?