This Man's Held You Back Your Whole Life.
- Mike Doyle
- Oct 20, 2019
- 1 min read
Ralph W. Wiley invented the electric traffic signal in 1921 in San Francisco. As seen at SFMTA Headquarters.
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Ralph W. Wiley invented the electric traffic signal in 1921 in San Francisco. As seen at SFMTA Headquarters.
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