7. Where tractor vehicles groom the surface of an Alpine ski slope, the operator shall comply with one of the following instructions:(1) he shall close the slope by posting pictograph 241 in Schedule 1 at the beginning of the slope and at each of its access points located at the same level as or uphill from the work area and by prohibiting access thereto by physical means at each of those places; or
(2) he shall post pictograph 273 in Schedule 1 at the centre of the beginning of the slope and at each of its access points located at the same level as or uphill from the work area and remove the pictograph as soon as the work is terminated and divert, by physical means, Alpine skiers from the work area.