In the mid-1960s the Alaska Railroad began using flat cars for vehicle shuttle service between Portage and Whittier. The "Whittier Shuttle" provided passage through Maynard Mountain via the Anton Anderson Memorial Tunnel. At Portage you would drive your vehicle onto a flat car and then take the short rail trip into Whittier. From there you could drive onto a ferry and cruise across Prince William Sound to Valdez where you would return to the highway system. This unique travel opportunity came to an end when the existing tunnel was converted into a combined highway and railway tunnel. and was opened to traffic on June 7, 2000.