Street Lighting

[W. K. Lis]

Chicago’s night sky is about to become an orange memory, as the city nears end of LED streetlight replacement. But are the new lights better?`

From link.

The city of Chicago is swapping its sodium vapor streetlights for LED streetlights. The lights on Irving Park Road at Lavergne Avenue are seen on Dec. 5, 2019. The nearest lights are LED and emit a neutral light while the more distant lights are sodium vapor and emit a yellowish light. (Terrence Antonio James / Chicago Tribune)

For almost two generations of Chicagoans, orange has been the color of night.

High pressure sodium vapor lights, which create a glow reminiscent of a tire fire, have lit Chicago since the 1970s. They have provided the backdrop for crime scenes, romantic encounters and waiting for a bus after a late shift. Chicago, viewed from the air, looked like a year-round Halloween display.

But in 2017, the city started swapping out the sodium vapor lights for energy-efficient LEDs, which create a whiter radiance. When the project is complete in 2021, the city will have replaced 270,000, or 85%, of its streetlights. As of mid-December, 185,000 fixtures had been replaced, said Chicago Department of Transportation spokesman Michael Claffey.

The new lights are saving the city $100 million over 10 years in electricity costs, Claffey said. They’ve also created better nighttime visibility and made streets safer for drivers, pedestrians, and bike riders, he said.

But the new fixtures use more of the shorter wavelength “blue” portion of the visible light spectrum, and questions have been raised about whether this could be harmful. Studies have shown that exposure to artificial sources of blue light, which is also emitted by personal electronic devices, can disrupt sleep patterns. The sun is the main natural source of blue light.

The new lights also have changed the look of the city. Not everyone thinks it’s for the better.

Ben Gonzales, a photographer and videographer, said that for his profession, the lights are good, and will probably help the television crews working all over town.

“Having brighter light is always going to be more beneficial as far as getting truer colors. The issue becomes that there’s been character that is lost when you switch away from the sodium vapor lights,” said Gonzales, of Humboldt Park, who owns Gopho Collective. "There’s this charm in the deeper amber color.”

Al Yellon, managing editor of the BleedCubbieBlue.com web site, spends a lot of time around Wrigley Field, where the lights were installed last summer. He’s a fan of them. “What a difference driving from an area where the lights light up everything to an area with those awful orange lights," he said.

Yellon said he’s also noticed that the new lights are more focused downward, so they don’t shine in his bedroom window like the old ones did.

Bernadette Libao of Logan Square, said she expected to be more nostalgic for the yellow lights, but isn’t bothered by the LEDs.

“I think they’ve grown on me,” Libao said. “They’re pretty bright."

Streetights on Irving Park Road looking east from Lavergne Avenue, shown on Dec. 5, 2019, are sodium vapor and emit a yellowish light. (Terrence Antonio James / Chicago Tribune)

Streetlights on Irving Park Road looking west from Lavergne Avenue, shown Dec. 5, 2019, are LED and emit a neutral-colored light. (Terrence Antonio James / Chicago Tribune)

The downward focus of the new lamps could cut light pollution and help people in Chicago see the stars better, though it’s too soon to know for sure, said Andrew Johnston, vice president of astronomy and collections at the Adler Planetarium.

The Adler plans to send up balloons over the city to see the effects of the new LED lights versus sodium vapor lights, and how much the light goes down instead of up.

The LEDs have been installed in multiple city wards on the South, West and North sides, including the Lakeview, Austin and Englewood neighborhoods, and along many major arterial streets, such as Irving Park Road, 55th Street and Cicero Avenue. Large portions of the Northwest and Southwest Sides, as well as the Loop and areas around the Loop, are still waiting for lights.

They consume 50 to 75% less electricity than the sodium lights, which is equivalent to taking 2,400 cars off the road for a year, according to the city. The new system also gives the city greater ability to respond to service requests, and allows lighting levels to be controlled remotely.

They provide a brightness level of 3000 Kelvin, which is how light’s color temperature is measured. High pressure sodium vapor lights are at around 2200 Kelvin.

Sodium lights first were installed on the Dan Ryan Expressway in 1969, replacing blueish mercury vapor lights, and went up around the city in the mid-1970s. Then-Tribune architecture critic Paul Gapp strongly objected to the sodium lights, comparing their light to the “bizarre paintings of Hieronymus Bosch, the frightening futurism of Stanley Kubrick’s A Clockwork Orange, and other nightmares.”

To replace the sodium vapor lights, the city considered 4000K LED lights during the procurement process, city spokesman Claffey said. The 4000Ks were tried in big cities like New York City and Seattle, where residents complained that they created the ambiance of a prison yard.

In 2016, an AMA report recommended that cities use 3000K or lower lighting. Dr. Mario Motta, a cardiologist and trustee with the American Medical Association, who co-authored a 2016 AMA report on LED lights, commended Chicago for choosing 3000K lighting, which was the best the city could get at the time.

“We wanted to be in compliance with the AMA report,” Claffey said.

Motta said the city “did the right thing."

But Motta said if he were writing the report today, he’d recommend LEDs that produce even less blue light, which have become more widely available.

“Nowadays, we can do better, ” Motta said. “I’d advise them to use the lowest ones they can get.”

Blue light creates more “scatter," which makes it more difficult for drivers over age 40 to see, Motta said. It also suppresses melatonin, the hormone that helps people sleep, and harms insects and other animals, Motta said.

“It’s environmentally toxic... ” Motta said. “The lighting industry was completely oblivious to the harm they’re doing with high blue lighting.”

Audrey Fischer, past president and current board member of the Chicago Astronomical Society, has been passionately vocal about her concerns, contacting city officials about what she sees as the need to swap out the current 3000K lights with LEDs with minimal blue light. Fischer has cited research that more exposure to blue light could increase the risk of cancer, mood disorders and obesity, as well as hurting people’s ability to see the stars.

“If they do the 2200s, we could restore starlight over the city of Chicago,” Fischer said. She said the city also could put “blue blocker” filters on existing lights.

Claffey pointed to research that electronic devices and indoor lights may expose people more to blue light than outdoor lighting.

Lumican, a Canadian company that makes 2200K LED street lights, said it gave the city a half dozen to test. But Claffey said the Lumican 2200K lights do not meet the city’s specifications, which call for 3000K. The Ameresco energy company is handling the contract, and acquires the lights for the city, he said.

Ald. Scott Waguespack, 32nd, said he wondered why the city could not at least try fixtures that produce less blue light in a few locations, to see how well they work.

“I don’t think the city does a good job of reaching out to companies and doing research into what’s quality and what’s not,” Waguespack said.

But Waguespack agreed that the LED lights he has seen so far in his ward are “definitely a lot better” than the orange sodium vapors they replaced.

 

[gabe]

I got to experience these new LED street lights over the Christmas break in Guelph. The new LED lights are great for drivers but horrible for pedestrians. The new LED's shine directly on the road making the road nice and bright. The old orange sodium lamps, lit up everything including the road, sidewalks and neighboring proprieties. As stated the new LED lights are more focused downward. i find the sidewalks and cross walks and properties are really dark. its bit like walking in a power outage. I think cites should install LED lights on the sidewalks for safety or just stick with the orange sodium lamps.

 

[W. K. Lis]

Optics for pedestrian crossings

The main purpose of street lighting is to create a safe and secure environment for people. Each project is unique and requires an individual approach. It is also important to take into consideration entrances and exits, footpaths and pedestrian crossings.

From link.

Lighting at pedestrian crossings is an important aspect in providing both pedestrians and motorists with a sense of safety. Because lighting is intended both to make pedestrians more visible to drivers as well as to light the way for pedestrians, it can sometimes be difficult to create solutions that meet everyone's needs. There are no standard solutions for lighting at pedestrian crossings; lighting must instead be adapted to the unique conditions at each location. As a starting point, it can be good to keep in mind pole placement, vertical lighting and increased lighting contrast around the crossings.

Requirements from the Swedish Transport Administration
For pedestrian crossings at intersections and roundabouts, a higher lighting class (higher technical quality of the lighting) is stipulated than what applies to the road in general.

Pole placement
A pole just before a crossing is usually preferable. The light then falls vertically on the pedestrians. A pole located before a crossing provides light directly onto pedestrians, which enhances colours and contours. With new installations, the poles are typically positioned 3 metres from the centre of the crossing on both sides for optimal results.

Vertical lighting of pedestrians
Lighting must ensure that pedestrians are visible both when they are on the road, as well as alongside it. By striving for high vertical illuminance, with the light falling on pedestrians coming from above and on the same side of the pedestrian crossing as approaching motor vehicles, it is easier to create a safe crossing.

Increased illuminance at pedestrian crossings
A general increase in illuminance at pedestrian crossings is often beneficial for pedestrians, but it requires careful planning in positioning the luminaires. The contrast between the lighting at a pedestrian crossing and other lighting should be carefully considered to avoid possible glare both for pedestrians and motorists.

Right lens at the right place
In creating optimal lighting solutions for each unique project, we have lenses especially developed for pedestrian crossings on roads with right-hand traffic. The lenses have high vertical illuminance and the luminaires are CLO-equipped with uniform light distribution.

 

[Divas S.]

Sauga has had them for a while now and sidewalks on arterials are a little bit darker now but the side streets are much much much brighter

 

[Northern Light]

LED is superior to High Pressure Sodium in so far as:

The light quality makes seeing things slightly easier
There is somewhat more energy efficiency
The fixtures themselves are changed such that light is less diffuse and more directed where needed.

However,

Making lighting less diffuse means creating more dark areas if no other changes are made.
The change in fixture type is not directly related to illumination type or LED.
IF you wanted to maintain previous lighting levels, at minimum, you would require more fixtures (more frequent poles) and/or additional pedestrian or directional lighting.

I favour seriously studying abandoning typical street lighting in favour of sidewalk and crosswalk lighting as I believe this may be safer and more energy efficient.

But I do say that is a preliminary conclusion and requires more intensive trials.

 

[ericmacm]

It's ultimately much a much better idea to keep street lights dimmer and more focused, especially with new LED bulbs, as well as only lighting what is necessary at night.

There needs to be a greater emphasis on light pollution and light reduction in urban centres and a balance needs to be struck, in terms of safety, psychology, and the environment. Yes, more lighting is safer for everybody, but it comes at the cost of light pollution, which may not seem like it would have a lot of effects upon first glance, but it is just as important as any other kind of pollution. We're moving in the right direction with the LEDs, but there's still a lot that needs to be done.

Getting rid of sodium bulbs was one of the best things to happen to urban lighting. They consume an excessive amount of energy, in addition to having an abysmal amount of wasted light that just ends up being directed towards the sky. LEDs have reduced energy costs significantly, but their effectiveness in reducing wasted light is dependent on if the direction of the light is controlled through reflectors and blinders. Some cities are good at implementing good light control practices, and some are not. Cities also light more things with LED lights as a result of lower energy costs, leading to excessive illumination. Wavelength is another important aspect of LED lighting, which is also highly variable between cities. The higher wavelength of blue-white/pure white light amplifies the effect of light pollution, and can technically be worse if light direction is not controlled. These temperatures of light also affect the human circadian rhythm negatively (mainly by affecting melatonin, the hormone that regulates sleep cycle), as well as bird migration and nocturnal animal patterns.

I can absolutely see LEDs continuing to be the sustainable way forward, but the emphasis on directional light control will need to be paramount in the future, as well as the use of lower temperature LEDs, such as temperatures below 3000k (redder wavelengths) for health and environmental purposes, and restrictions on light intensity.

 

[ruckus]

not enough talk about the benefits of less light pollution, can't wait until Toronto makes the change!

 

[Northern Light]

Was out and about today; (October 31st, 2020) and noticed Hydro has changed over the streetlights in an entire neighbourhood.

The one located north of St.Clair Avenue East and south of O'Connor drive (wedge shape)

One close pic; and one showing that the new fixtures for 2 blocks or more down the street:

 

[ruckus]

could it be??? LED streetlights??

 

[Northern Light]

could it be??? LED streetlights??

I would think so.

But would have to be by in nighttime conditions to assess.

I don't see any pages on Toronto Hydro's website referencing the streetlighting replacement program.

 

[ruckus]

same, will hopefully make a difference with the light pollution

 

[11th]

I would think so.

But would have to be by in nighttime conditions to assess.

I don't see any pages on Toronto Hydro's website referencing the streetlighting replacement program.

They had a page - albeit not a very informative one. Seems like it was removed last time they revamped their website.

 

[Northern Light]

Was out and about today; (October 31st, 2020) and noticed Hydro has changed over the streetlights in an entire neighbourhood.

The one located north of St.Clair Avenue East and south of O'Connor drive (wedge shape)

One close pic; and one showing that the new fixtures for 2 blocks or more down the street:

View attachment 280067

I would think so.

But would have to be by in nighttime conditions to assess.

I don't see any pages on Toronto Hydro's website referencing the streetlighting replacement program.

So, I happened to pass through this area again late this afternoon, and it was dark, the fixtures illuminated.

So I can confirm they are LED; they provide a fairly warm white light.

Pictures below:

Without any tall buildings near by, tough to tell how much reduction in light pollution there may be.

But I consider the fact that I can see the strong glow of the light itself several poles away a bit of a disappointment. (ie. the light should more downwardly focused.)

 

[nfitz]

I thought they'd started switching to LED 2-3 years ago. When all the bulbs suddenly got changed, the lights got brighter and a bit biter, and they didn't ever seem fail as frequently. At least along Upper Gerrard.

 

[Northern Light]

I thought they'd started switching to LED 2-3 years ago. When all the bulbs suddenly got changed, the lights got brighter and a bit biter, and they didn't ever seem fail as frequently. At least along Upper Gerrard.

I'm not sure if they've done any refits on the Acorn fixtures.

What I took note of here was a modified version of the Cobra fixture; (which is what was replaced), with the same bracket, but no protruding lens/bulb.