La. R.S. 45:693

All street railway companies operating street railways in cities of population of one hundred thousand or more, shall equip all street railway cars running by motor and controlled by electric power with sandboxes in front of the wheels coupled to and controlled by motor. These boxes shall be provided with valves from which the sand therein may be poured upon the rails immediately in front of the wheels of the car as the brakes are put on by the motorman for the purpose of stopping as necessity may require.