Despite the success of the Broadway pedestrian plazas in Manhattan, in general, pedestrian malls, in which all traffic is removed from shopping streets, have not been successful, leading to the conclusion that only particular areas – such as in college towns and resorts, which already have sufficient population density or pedestrian traffic – can successfully pursue this path. Of the approximately 200 pedestrian malls created from the 1970s on, only about 30 remained as of 2012, and many of these were in poorer areas of their cities. The exceptions, including the Third Street Promenade in Santa Monica, California and 16th Street in Denver, Colorado, are indicators that conversion of shopping streets to pedestrian malls can be successful, although the proper preconditions must exist. Some of the failed pedestrian malls have improved by allowing limited automobile traffic to return.