ECN Forum Forums General Topics of the Trade General Discussion Area LED Traffic Signals

They installed the LED traffic lights here in Bergen County, NJ a year or two ago. In traffic lights the county owns. Town owned light are still light bulbs.

When listening to a distant AM radio station at night in the car, I hear some RFI from these LEDs when sitting at a red light or crossing the intersection.

Here in Washington State there has been a huge push to LED signal illumination, I believe for both operating and maintenance costs. The power savings, as spread over the state, are tremendous!

The sudden "snap" effect also caught my attention a few years ago and sure enough it was a LED head.

Another interesting item I spotted a couple of months ago was a red LED beacon mounted atop a "STOP" sign and it was solar/battery powered! Definitely needed where it was, too- the sight distance was terrible on approach to the intersection. I would like to see more of these in use.

Here in New York I see some have been converted. I have also seen a few incandescent reds that have been fitted with a strobe tube across it's face. These flash when the red is on. They do this at locations of poor visibility.

On the subject of LED's, Many high end cars are now using them for brake lights. I first started noticing them on some trucks like UPS and FEDEX.

You can always spot these by their instant on/off operation which is quite different than the familiar incandescent.

-Hal

 
Up here in Northwestern-Central East California, all the new development is pure LED, but the “blast-on” feature—that would surely decimate incandescents—seems to have gone out of style.

I understand that Hewlett-Packard {LEDs and everything else} and CalTrans {state road dept.} did a lot of development work up to several years ago. A ~100K town in the region carried an evening news report of getting a $150K rebate for signal retrofits from PG&E [“inspired”/ramrodded by the state energy commission, no doubt.]

For retrofits around here, changeouts are not wholesale in the heads—some green, some red, some both, fewer amber—but way too many obnoxious ADA “chirpers.”


[This message has been edited by Bjarney (edited 12-31-2004).]

Out here in Winnipeg MB it seems that they are being replaced as they burn out or if the signal pole gets hit the whole head gets replaced with LED. And of course new signal constructon gets the LED head as well.

The City of Winnipeg signals department also says that they can save money on pedestrian crossing heads by removing one of the two bulb ones on each pole and putting a single LED walk don't walk matrix head in. They try to do this when they have to relamp a head. From what I read in the newspaper the signals deptartment figures by doing this they won't have to buy new heads for about 8 or 9 years.

It looks a little funny as on one side of the street there is the normal two head pedestrian signal and the other side has the single walk don't walk head.

A few years the city of Chico,(CA)replaced the incandescent lamps w/ LEDs in their signals it took a bit of getting used to.

Noticed LED traffic signals appearing over here in Scotland over the last couple of years.

The thing that grabs my attention is the amount of signals that are unlit.

At a junction near my home all the greens were out for days. Not long after they were repaired some of the ambers were out.

I have noticed this at several sets of lights, some new installations and some converted.

Wishing everyone a happy new year.

simon.

My nearest traffic lights are about 10 miles away -- Only three sets in that town, and all still filament lamps. But in the city (Norwich) about 20 miles distant I've noticed that LEDs have started replacing regular bulbs the last couple of years, sometimes just one or two aspects. There's one particular set of lights on the ring road which is completely LED on every post, all regular aspects and the left/right-turn arrows.

Are they the annunciators which sound when the "WALK" sign is illuminated? We've had those on our "Pelican" crossings in Britain for quite a few years now, probably since about the 1980s. ("Pelican" crossings are lights placed mid-block to stop traffic specifically for pedestrians to cross.)

Almost all the new cars here for the last couple of years seem to use LEDs for the third, high-level, center brake light. The regular brake lights are still filament bulbs on most, although I've seen a few equipped with both LED brake and turn signals at the rear (all current cars made for Europe have independent amber turn signals, by the way).

I often find the green LED traffic lights excessively bright at night. I believe that the LEDs have been getting more efficient, but the power levels have not been cranked down to compensate. Also, of course, this same 'excessive' brightness is quite nice during the day.

-Jon

Interesting. I've read in our state DOT specifications about 150-watt amber flashing beacons having a dimmer function for what I believe is the same reason. I wonder if the spec will change when amber LEDs are used in this capacity...