Traffic Light System Developments Highlighted in Germany

The International Day of the Traffic Light is observed on August 5, marking the evolution of the red‑green‑yellow signal that now governs road traffic worldwide. The first electric traffic signal was installed in Cleveland, Ohio, on August 5, 1914, and the addition of the amber caution light was pioneered by Detroit traffic officer William Potts in 1920, creating the three‑color system used today.

In Heiligenhaus, Germany, the city has introduced a "dark traffic light" at a busy pedestrian crossing. When the signal is off, pedestrians may cross the road using the crossing island as they would at an unsignalised crossing, remaining responsible for safety. Drivers can activate the light with a button when they need the crossing to be protected. The system is intended to improve flow on a heavily used route connecting a college campus, a shopping area and the town centre.