Andrew Gabriel wrote:
In article ,
The Natural Philosopher writes:
stevelup wrote:
Surely the primary reason for using them in traffic lights is to reduce
ongoing maintainance costs?

Yes. Unfortunately, the first generation turned out to be very
short lived before the LEDs died.

That as well.
But there are enormous energy savings to be had as well.

Traffic lights are not normally on a metered supply in this country.
This was an important reason in the US, where they are more often
metered, and where they use inefficient mains bulbs. UK traffic
lights have used LV halogen bulbs for decades, which are much more
efficient than mains signal bulbs in the first place.

Not significantly when they've got a filter over the front.