The last major alteration to the Ridge Route began in the early 1960s. By then, the plan for a six-lane freeway had expanded to eight lanes. This construction project made the most changes to the route. Many of the curves that followed the mountainside were cut through. To climb the mountain on the south side of Castaic more easily, traffic lanes were reversed (southbound lanes to the east and northbound lanes to the west). To prevent head-on collisions, the two ends of the route were separated on two different mountainsides, and the section through Piru Canyon was moved to an entirely new alignment to make room for Pyramid Lake. The project was completed by 1970 and brought the Ridge Route to its current alignment.