who invented the traffic signal
The traffic signal does not have a single “one” inventor; several people created key versions over time, but two names usually stand out: James Hoge, who is widely credited with the first electric traffic signal system in 1914, and Garrett Morgan, who later patented an influential three‑position automatic traffic signal in 1923.
Quick Scoop
The short answer
If you’re asking “who invented the traffic signal,” most modern explainers highlight a chain of inventors rather than one lone genius.
Here are the big milestones:
- 1912: Lester Wire builds an early electric red‑green traffic light in Salt Lake City.
- 1914: James B. Hoge’s electric traffic signal system is installed in Cleveland and is often cited as the first electric traffic signal in real‑world use.
- 1920: William Potts creates the first three‑color (red‑yellow‑green) electric traffic light in Detroit.
- 1923: Garrett Morgan patents an inexpensive, automatic three‑position signal that adds an all‑direction stop for safety and later sells his patent to General Electric.
Why it’s “complicated”
Different sources emphasize different people because they focus on different questions:
- “First electric traffic signal in a city street?” → James Hoge in Cleveland, 1914.
- “First three‑color light like today’s?” → William Potts in Detroit, 1920.
- “Famous patent for an automatic three‑way signal and a pioneering Black inventor?” → Garrett Morgan , 1923.
So when you see schoolbooks or quick posts saying “Garrett Morgan invented the traffic signal,” they are usually talking about his specific three‑position, automatic design that added a safety pause, not claiming he was the first person ever to control road traffic with lights.
Key inventors at a glance (HTML table)
| Inventor | Year | What they did | Why it matters |
|---|---|---|---|
| Lester Farnsworth Wire | 1912 | Built an early electric red‑green signal in Salt Lake City. | [2]One of the first known electric traffic lights, manually operated. | [2]
| James B. Hoge | 1914 | Designed an electric traffic signal system installed in Cleveland, often called the first electric traffic signal. | [1][5][2]Brought electric traffic control into real city streets, with coordinated corner posts. | [5][8][1]
| William Potts | 1920 | Created the first three‑color (red, yellow, green) electric traffic light in Detroit. | [9][6][2]Introduced the color scheme and multi‑direction setup that shaped modern signals. | [6][2]
| Garrett A. Morgan | 1923 | Patented an automatic three‑position traffic signal that stopped all directions before allowing movement. | [3][4][7][2]Improved safety with an all‑stop phase; sold to General Electric and helped spread automated signals. | [4][7][3][2]
Little story to remember it
Imagine a timeline like a relay race:
- Lester Wire sets up a basic electric red‑green box in 1912, showing that lights can control cars.
- James Hoge grabs the baton in 1914 and gets the first well‑known electric system running at a busy Cleveland intersection.
- William Potts adds the crucial yellow light in 1920 so drivers get a warning instead of an instant change.
- Garrett Morgan refines the idea in 1923 with an all‑direction stop and an affordable design that big companies can deploy widely.
That’s why, in 2026, when someone asks “who invented the traffic signal,” the most accurate answer is: it was built step‑by‑step by several inventors, with Hoge, Potts, and Morgan as the most influential names.
Bottom note: Information gathered from public forums or data available on the internet and portrayed here.