Friday, June 19, 2015

Neighors Dislike New Ultra Bright LED Street Lights Resulting In Glare

Arterial LED Street Light

The Laurelhurst Blog has received several email about the new lights recently installed in various parts o f the neighborhood;

One resident on 47th Avenue NE near Sand Point Way said:

In the last few days we've noticed that they've changed out the street lights on our street.  Gone are the soft lights that you see on Sand Point Way. They've been replaced by ultra-bright "stadium" white lights.  It's too bright and shines through our closed blinds in our bedroom.  Very annoying.  Does anyone know if this was done as a cost saving measure?  Does anyone dislike it besides me?

Another resident said:
I am wondering about the new LED lighting being installed in the neighborhood.  I think it's along the bus route.  The glare is very bad.  There are two styles of lights, one has 3-5 rows; the other has 5-8 rows.  
There is one on NE 41st Street and 37th Avenue NE by the Center for Urban Horticulture.  They make the neighborhood look like an airport runway.  I've called City Light and they’ve said there have been many complaints. 
The Laurelhurst Blog contacted Mark Vanoss, who gave this information:

The City has been converting the streetlights from high pressure sodium (HPS) to light emitting diodes (LEDs) starting in late March 2013 for Laurelhurst and Sand Point, which lie in Zone 3.

Work in Zone 3 is being carried out based on City Light’s established four year maintenance cycle.  From the map, one can see that conversion of the arterial roadway streetlights in this area is recent. Non-arterial (residential) roadways were converted to LEDs starting as early as late 2009. There are still some residential streetlights out there in isolated pockets. These will be converted as they are identified while the contractor is working on the arterial conversions.

Zone 3 is in our four-year maintenance schedule and the HPS fixtures (called cobrahead) are being replaced with long life (expected 15 year life) LED fixtures rather than replace lamps (every four years) with HPS cobrahead fixtures.

The City of Seattle sets regulations based on national standards for how much light should be provided on roadways to maintain safe driving conditions and ensure pedestrian safety. City Light has a responsibility to follow those standards. The Seattle Department of Transportation (SDOT) has primary responsibility and the authority to determine lighting needs and design criteria necessary for traffic safety for arterial and business district lighting. The design criteria include setting light levels, light quality, uniformity, performance of luminaire lighting distribution, and illuminance criteria. A thorough lighting level analysis was performed and SDOT determined the proper LED wattage for the roadway.

If bright lights are affecting customers, they  can file an on-line report or call 206-684-7056If there are specific LED streetlights that are causing light trespass (glare) problems on a customer’s property, City Light may be able to help but would need more information. Customers can report via the on-line form or by calling 206-684-7056.

Necessary information to file a complaint:
  • Your property address, include unit number and floor if applicable                                                                         
  • 7 digit pole tag number from each pole that is affecting you or your property, yellow tag, black numbers                                           
  • What parts of your property are affected, living room, 2nd floor bedroom, deck, front yard, etc. 
  • Daytime phone number
Once this information is received it will be forwarded to City Light’s Resident Engineer to assess and determine that proper installation, light function and performance of the newly installed LED streetlights meet City Light’s standards. There is a burn-in period for the new LEDs. They are brighter at initial installation and usually takes up to 45 days to calm down.

Before selecting these lights, the utility tested multiple lights from several different manufacturers and with several different color temperatures. Surveys of residents and business owners in pilot areas helped City Light in considering the needs and desires of the community and had a direct impact on the Correlated Color Temperature (CCT) selection. While this is still a significant change from the amber high-pressure sodium lights they are replacing, the new white color has been popular with our customers.

LED streetlights improve safety for drivers and pedestrians by enhancing depth of field and peripheral vision. They also provide truer color rendition than the high-pressure sodium lights. The LEDs use about 60 percent less electricity to operate and last at least three times longer than the high-pressure sodium lights. That means a significant reduction in operating and maintenance costs for the City -- and by extension customers. Unlike the old HPS lights, the new LED lights are dark sky compliant and meet all requirements set by the International Dark Sky Association.

Benefits of LED conversion include:
  • High-pressure sodium luminaires, most installed in the mid-1980s, are at the end of their useful lives and failing. LEDs will provide better service reliability and lower maintenance costs.
  • Reduction in greenhouse gas emissions:
  • In manufacturing,
  • When LEDs are in use,
  • Fewer service vehicle trips for repairs will mean a reduction of about 20,000 tons of carbon each year
  • Replacement of luminaires with LED fixtures will provide three to four times longer field life than high-pressure sodium
  • LEDs are not affected by truck and roadway structure vibration
  • Better light quality (whiter/cooler color rendering)
  • Light quality improves safety because of depth of field and peripheral vision enhancements without distorting color
The previous high-pressure sodium lights in residential areas provided an amber colored light. Interestingly, when Seattle City Light changed to those lights some 30 years ago from mercury vapor lights, which produce a white light, we received many complaints about the color difference. This is to be expected. We all become adjusted to the color of our streetlights and recognize significant changes quickly.
Here is the schedule for future arterial conversions to be completed in 2-3 years.

For more information go here:

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