Personal Report

17 giugno 2010

L’invenzione del semaforo stradale

Design Observer racconta in un breve articolo l’invenzione del semaforo stradale ad opera di Lester Wire, poliziotto di Detroit, quasi cento anni fa.

The traffic signal was first invented in 1912 [...] as a two-color light to warn pedestrians ahead of the impending transition. In 1920, this basic design was modified (by another policeman named William Potts) to include the tri-colored red, amber, and green lights widely used today.

This simple, three-color icon has endured for nearly a century with relatively little change, save for the incorporation of modern technologies such as automatic timers, diode lights and motion sensors. The core of the three-color traffic remains true to the initial vision of two smart American policemen.