Although to many people today, it might seem unbelievable that people got into accidents in the time of the first automobiles, the truth is that accidents were fairly common in those days.  Traffic safety measures were implemented almost immediately after the advent of cars.  The first automatic traffic signal system was created in 1910 by Earnest Serrine and used the words “stop” and “proceed” to direct traffic.  These words were not lit up on the signal, which limited their effectiveness.  The first signal using red and green lights was invented in 1912 by Lester Wire.  Finally, the yellow light was introduced in 1920 and was employed by William Potts in his 4-way models.  However, Garret Morgan was the man credited with leading to the widespread use of the traffic signal, as he was able to create a model that was cheap and easy to manufacture.  This manual system displayed the words stop and go and also had a setting to stop traffic in all directions so that pedestrians could cross.  This type of signal was replaced by the automatic red light, yellow light, green light variety that we are used to today.

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