The 1920s are well known as a decade when automobile ownership in the U.S. skyrocketed, especially with the production of Henry Ford’s Model T. But an equally fascinating aspect of the story is how municipalities tried to cope with the sudden explosion of automobile traffic on the streets. All of the road signs and signals that we are so used to seeing today–a double yellow line down the center of the road, a white pedestrian crosswalk, the traffic light in the intersection–did not simply spr...