Nov. 20: Garrett Morris’ automatic three-position traffic light wins a patent on this date in 1923

By 1923, traffic congestion from cars was strangling the business districts of many U.S. cities. In most downtowns, police had adopted a system of lights switched by hand -- in the belief that motorists would not obey a signal if there wasn't a policeman present. Cleveland businessman and inventor Garrett Morris improved on those ideas with a three-position "semaphore" type light that offered a type of warning that yellow lights do today, or could be set in a caution mode when unattended. His key innovation wasn't the yellow light, but the system's automation; not only were timed lights better at handling traffic, they couldn't discriminate against black motorists -- like Morris.