Let there be light, but not too much: Looking for balance in street light brightness
FARGO — When construction workers reopened a section of Broadway just north of Fargo North High School last fall, motorists found twice as many street lights as before and the light is now really bright.
The city had added light poles and replaced dim yellowish sodium-vapor lamps with white LEDs, which it says provide more light but use less energy.
Some area residents say they want more.
"There is one street light in our area, it barely lights up anything," Denise VanderBush, who lives just east of Broadway, told The Forum via the Nextdoor social media website. "If my neighbors don't have their outside house light on it is really dark on the sidewalks, driveways and the street."
Others caution there can be such a thing as too much light.
"Driving at night bright lights make it more difficult for the eyes to transition between the normal night driving then coming across a bright light then back to darkness again," Anthony Wiese, who lives in an adjacent neighborhood, said on Nextdoor. He said he worries pedestrians would be at risk.
The American Medical Association has also expressed concerns about the impact of glaring lights on people's health and on wildlife that depend on darkness to hide from predators and breed.
Dave Helland, who oversees street light design for the city of Fargo, said concerns about bright lights have not escaped the city as it adds new street lights and converts old ones to LEDs. But finding a balance, he said, has become easier as LED technology rapidly advances.
Moorhead and West Fargo are also converting their street lights to LEDs, officials there said.
Health, safety concerns
The problem with bright lights is not specific to LED street lights.
Researchers have found that bright lights, especially the bluish light of computer and cell phone screens, can disrupt the natural sleep cycle, according to the AMA. Long-term disruption has been linked with an increase in the risk of cancer, diabetes, heart disease and obesity.
Street lights, which have long used mostly energy-efficient sodium lamps, are increasingly being converted to even more efficient LEDs. This adds a new source of bright light at night, as LEDs can be much brighter even while using less energy. Early models of white LEDs, preferred because they seem more natural than colored LEDs, tend to have a bluish tinge.
In an advisory released in June, the AMA recommended cities use LED street lights with "warmer" tones and avoid making them too bright. The U.S. Department of Energy, which has championed LED conversion, and the National Electrical Manufacturers Association have both said they agree in general with the AMA.
Helland said he agrees also, if only because bright bluish lights appear harsh to the human eye and can be a safety concern. "The harshness of the whitish to blue," he said, "that part I truly do feel is not good for anybody for driving." It's especially bad for older drivers, he said.
The city converted its first street lights to LEDs seven years ago along a stretch of Broadway downtown where the lighting was already bright and harsh, he said. But he hesitated to recommend the city convert more street lights until LEDs with warmer tones became more common and affordable, he said.
"It's been on my mind over the years, much before hearing of and reading the so-called health reports by the AMA," he said.
Though LEDs seem to have gotten a bad rap, they are actually better in many ways than the lights they replace, Helland said. They use less energy and last longer — 15 years compared to two to three years — saving the city both energy and the labor cost of replacing bulbs. And they can be designed so they focus light only on areas the city wants lighted, say, away from residents' windows.
Eager for light
Many residents are eager for the additional light.
Helland said he's heard few complaints about new LED lights but a lot of demand for them or just any lighting, especially in the Roosevelt neighborhood near North Dakota State University. Older parts of town have fewer street lights because the city traditionally mount lights on utility poles, which are placed farther apart than purpose-built light poles in newer parts of town, he said.
Roosevelt residents have complained of more crime, both petty and serious. In 2015, after two homicides in the areas highlighted residents' concerns, police recommended the city install more lights to deter criminals.
They got some but not enough, they said.
"Our neighborhood could still use more," said Brianna McAleer on Nextdoor. "Lots a street traffic and with so many of us 'fixer uppers,' the vandalism over the years is just annoying. The one lamp that was added to our street has already helped lessen disturbances."
From her perspective, she said, "the brighter the better!"
On the Web: To read the AMA recommendation, go to " target="_blank">bit.ly/2cTVMHD.