How bright is too bright when it comes to lighting on the new SR 520 bridge? The answer depends on who you ask.
"It looks like a row of parked cars with their lights on bright, stretched all the way across the lake," said Laurelhurst homeowner Jim Bradburne.
He's one of several neighbors living on the north side of the bride who feel the lights are far too bright. Bradburne says it's more than a nuisance in the lakeside community. He also worries about the environmental impacts.
"My first reaction was wow this can't be good for the fish," he said. "I'm a fly fisherman, and I saw the lights and I knew it would have an impact. Increased artificial lighting has a tendency to attract the fish around the lights. That has the potential, studies have shown, to increase the predators that can easily come in and wipe out juvenile salmon that are trying to survive in the lake and ultimately make it to saltwater."
WSDOT is well aware of the concerns. In fact, the complaints started coming in almost immediately after the lights were turned on.
"So fairly shortly thereafter, there were tests conducted," said Larry Kyle, who is the SR 520 Program Engineering Manager.
As a result of those tests, he says WSDOT changed out the lightbulbs in June, going from 100 watt bulbs down to 50.
Kyle says the roughly 200 lights installed on the new bridge and are intended to illuminate the pedestrian and bike path and maintain safety requirements on that path.
He says WSDOT did extensive research on potential environmental impacts of the lights.
"We feel very comfortable in saying that we have minimized the potential negative impact on the salmon in Lake Washington," said Kyle. "Because we are well under the light levels that are indicated that might cause salmon to change their behavior. That would be a concern."
Also frustrating to Laurelhurst neighbors is that the bicycle and pedestrian path does not yet fully link Medina and Seattle. The part that is open right now is an "out and back" trail from Medina to the west end of the floating bridge.
"Our idea is to just close it, until the path becomes fully operational," said homeowner Colleen McAleer. "Turn off the lights, give time for a solution to be found, and then move on. In the meantime, we're not sure why the path would be lit at all."
Kyle says it's not quite that simple, since bicyclists and pedestrians are already using the portion of the Regional Shared Use Path that is open.
"I think we'd like to tell these neighbors that we understand their concerns, we appreciate their input, and we're trying to balance the aesthetics of the appearance of lights north of the bridge with the needs of other users and the safety of other users," said Kyle.
According to WSDOT, between 200 and 400 bicyclists per hour will be using that lighted trail during commute times, once it opens up all the way to Seattle."
He says WSDOT will continue to analyze the lighting and consider alternatives. One possibility is making adjustments to the lighting fixtures.
"The light fixtures are designed so they have a shield across the top portion of the fixture, and part of the bulb is shielded," said Kyle. "The intent is to have the light shining down on the path and unfortunately, the shield on this particular fixture doesn't cover the whole lightbulb, and I think that's part of the reason it's fairly visible from the north side of the lake."
WSDOT hopes to have another update for neighbors by the end of October.
"This lighting is just nothing like what we had seen in the environmental studies early on in the design process," said McAleer. "And with this kind of lighting, reducing the wattage just isn't enough to correct the problem."