Since the 1950s, as Interstates were being constructed, sections of US 66 not only saw the traffic drain to them, but often the route number itself was moved to the faster means of travel. In some cases, such as to the east of St. Louis, this was done as soon as the Interstate was finished to the next exit. The displacement of US 66 signage to the new freeways, combined with restrictions in the 1965 Highway Beautification Act that often denied merchants on the old road access to signage on the freeway, became factors in the closure of many established US 66 businesses as travelers could no longer easily find or reach them.