LED streetlights as much about safety as savings

Driving under traditional amber-colored lights can really
play tricks on the eyes. You go from light to dark over
and over again because the bulbs are focused straight
down, creating gaps. The light never covers the entire
street.

But energy efficient LED lights provide a much larger
field of light, and they can be positioned to cover
exactly what is needed.

Seattle City Light’s Scott Thomsen said the city has
already replaced 20,000 residential streetlights with
LEDS, and it should have all the city’s neighborhoods done
by 2014.

The city expects to save over $2 million a year in energy
costs by making this move, and it’s testing the lights on
the arterials with the goal of replacing every streetlight
in the city with LEDs.

But Thomsen says improving safety is just as important as
savings.

“More depth of field that you have, how much better your
peripheral vision and how much easier it is to spot
something in the roadway,” he said. “A pothole that you
need to avoid as a driver. Whether it’s an animal that
has run out into the street. Whether it’s a bicyclist or
a pedestrian on the side of the road.”

The police really like these new lights because they
provide a truer color to the eye. You can make out the
colors of clothes and cars from much farther distances.

But as you’ve probably noticed with LED lights at your
home, they come in all shades of white. Thomsen said the
city ran into trouble with their first attempt.

“Some of the most energy-efficient lights were a very cool
color, a little more on the blue end of the scale,” he
said. “Particularly in one area of Capitol Hill, people
really did not like what they called ‘zombie blue.'”

The city tweaked the lights to a more pleasing shade of
white. They now give off light very close to moonlight.
Thomsen said the new lights will pay for themselves in
about seven years.

“You get a better quality of light,” he said. “You get
more reliable service . You use a lot less energy, and it
saves you a lot of money.”

Another feature these LED’s have over traditional bulbs is
that the city can program them to meet traffic patterns.
They can turn up or turn down their intensity so they’ll
be their brightest when the most cars are on the road and
a little softer but still bright enough to provide safety
the rest of the time.

And for those of you who are concerned these brighter
lights will increase light pollution, Thomsen said the
light can be angled so they don’t project above the
fixtures.