If you are up on 18 after upper Waterman there is almost no protection on the side of the road when you get to old county yard, the sharp hairpin after the big S turns. And there isn't much shoulder between Panorama Point and the 138 bridge. If you plan to continue on up to Arrowhead it is still a better bet to drive through Crestline than to stay on the narrows because the cars do not give you any room. But the ride down from 138 is one sweet ride, if you trust your tires.