Since there are hundreds of historical signal photos, they will be organized by decade, in ascending order. If the image is pre-google maps streetview, it will count as historic. Images courtesy of Temple University Digital Archives, others courtesy of their rightful owners and photographers.

1930s

1940s

1950s

1960s

1970s: https://keystonestatetrafficsignals.com/2020/10/15/historical-signal-photos-1970s/

1980s

1990s

2000s