Since the reign of Queen Anne (1702-1714) there have apparently been 37 Acts of Parliament regulating hackney carriages which are still supposedly in force for taxis today.
1. It is illegal to hail a cab whilst it is in motion. You should wait at the "place appointed." The taxi rank should also provide a water trough for the horses to have a drink.
2.The cab driver is supposed to ask you if you have any "notifiable diseases such as smallpox or the plague." As carrying sufferers is illegal, he should refuse any who look infected because if you die on the journey he will be committing the offence of carrying a corpse.
3. The law requiring a taxi to carry a bale of straw on top to feed the horse was only repealed in 1976, as was the requirement to have a nosebag of oats on the side of the cab. The stricture to have "sufficient foodstuffs for the horse" was in modern times interpreted as having enough diesel or petrol.
4. A cabby who drives too slowly could be convicted of "loitering" and one who drove too fast of "furious driving." It is expressly forbidden for a driver to make "insulting gestures."
5. Because it was illegal to leave a hackney carriage unattended on the highway, the driver was permitted to urinate in public provided that he was by the rear wheel of the vehicle with his right hand place upon it.
With thanks to "The Strange Laws of Old England" by Nigel Cawthorne.