Puzzling road-related offences, excessive council regulations and outdoor dining laws that border on the bizarre - Sydney has become so bogged down by "nanny state" rules that people can break the law up to 10 times a day, without realising.

While debate rages over the strict lockout laws governing licensed venues, there is a lesser talked-about tier of red tape that Sydneysiders are often oblivious to - until they are tapped on the shoulder and hit with a fine.

A beautiful summer's morning can suddenly turn foul, if you beep your car horn and wave hello to a neighbour.

Why? Because under NSW road rules, illegal use of a "warning device", attracts a $298 fine and three demerit points while a "limb protrude" from a vehicle is punishable by the same sum - even if it is an elbow resting against a car window.