1900-1930: The years of driving dangerously (http://www.detroitnews.com/story/news/local/michigan-history/2015/04/26/auto-traffic-history-detroit/26312107/)
QuoteThe very first gasoline-powered vehicle driven on the streets of Detroit was built by engineer Charles Brady King in 1896. It went as fast as 20 miles per hour, which was described in the newspaper as "tearing along the street at a lively rate, dodging people and teams."
The transition from the horse age to the motorized age would prove to be very dangerous. At first speeding vehicles were not a big problem, with only a few of them on Detroit streets, but the situation grew serious quickly.
As early as 1908, auto accidents in Detroit were recognized as a menacing problem: In two months that summer, 31 people were killed in car crashes and so many were injured it went unrecorded.
Then traffic control came in handy.