(2)Whoever, in driving leading or propelling vehicle along a street, fails without reasonable excuse -(a)to keep to the left, or(b)when he is passing a vehicle going in the same direction, to keep to right of that vehicle,shall be liable to a fine which shall not be less than twenty-five rupees and more than two hundred rupees.Exception. - This sub-section shall not apply to a municipality wholly or in part situated in hilly tract.