The traffic light doesn’t have a single “creator” – several inventors contributed key versions over time, depending on whether you mean the first signal, the first electric light, or the modern three‑color system.

Quick Scoop: Who created the traffic light?

  • The first traffic signal (non‑electric, gas-powered) is usually credited to John Peake Knight, a British railway engineer, who installed a signal outside the Houses of Parliament in London in 1868.
  • The first electric traffic light is widely credited to Lester Farnsworth Wire, a police officer in Salt Lake City, who built a red–green electric signal around 1912.
  • The first four‑way, three‑color (red–yellow–green) electric signal was created by Detroit police officer William Potts in 1920, adding the yellow “caution” light that became standard worldwide.
  • The influential three‑position automatic system (with a dedicated “all stop” / caution phase between stop and go) was patented by Garrett Morgan in 1923; his work helped popularize safer, more automated urban traffic control.

So if you’re answering in one line, a common shorthand is:

  • John Peake Knight invented the first traffic signal (1868),
  • Lester Wire built the first electric signal (1912),
  • William Potts and Garrett Morgan shaped the modern three‑color, automated traffic light in the 1920s.

Information gathered from public forums or data available on the internet and portrayed here.