 By 1965, US-40 and US-40A switched routes; henceforth, US-40 would run along current-day SR-186 until it was truncated in the mid-1970s.In 1966, the State Road Commission extended the route southwest on a proposed roadway to I-215, but the Bureau of Public Roads denied the request to build it with federal aid because placing an interchange at that location on I-215 was infeasible, and it was cut back to SR-68 in 1967.North Temple Street west of 300 West (then US-89/91, now solely US-89) was added to the state highway system in 1931 as part of SR-67.