When conditions are green, roads are passable and normal operations are in effect. When conditions are amber, roads are passable but with difficulty and slippery conditions exist, and MP patrols may remain stationary. When conditions are red, roads are impassable and only installation and tactical vehicles will travel, and MP patrols will remain stationary unless dispatched. When conditions are black, roads are impassable and only installation vehicles will travel, and MP patrols will remain stationary unless dispatched.