law: 291. Traffic rule of the road.
  Whoever in driving, leading or propelling a vehicle along a street fails, except in a case of actual necessity,
  (a) to keep to the left when passing a vehicle coming from the opposite direction; or
  (b) to keep to the right when passing a vehicle going in the same direction as himself, shall be punishable with fine which may extend to five hundred rupees.
  Prevention of fire, etc.