Earliest LEDs

[traffic light guy]

The earliest I've seen are near Philadelphia, the signals themselves probably have been retrofitted with these LEDs in the early-2000s, whereas Philly didn't retrofit their older installations until 2010.

[M3019C LPS20]

In New York City, in 1997, the Department of Transportation first experimented with LED inserts. In the borough Queens, all existing traffic signals were retrofitted with red LED inserts. If memory serves me right, they were manufactured by Precision Solar Control.

After three years, the D.O.T. came to the conclusion they were energy efficient. Thus, in the following year, in 2000, the citywide conversion commenced.



Outside of New York City, the first LEDs (only red) appeared as far back as to 1989 AFAIK.

[DaBigE]

Madison, WI started in the late 90s...'97 or '98 and just with the red and green balls and a handful of ped signals. The red and green balls were the type with a dense cluster of LEDs in the center-most portion of the ball (4-6" diameter) and a more spaced-out matrix making up the balance of the LED ball. To this day, there are still quite a few intersections around Madison with only the red and green balls as LED and the arrows and yellow balls as incandescent. There's a few incandescent ped signals around, but they are very, very few left...about as many as ones that haven't been converted to symbol signals.