SEATTLE — The Washington Department of Transportation will soon be installing brighter lighting inside the Mount Baker and Mercer Island tunnels as part of the ongoing I-90 project.
Drivers said this is a welcome improvement, as the contrast between the dark tunnel and the brightness outside often creates a traffic slowdown with people pressing on the brakes as they adjust their eyes.
“If I keep my sunglasses on in the tunnel, I can’t see. So I take them off, it’s all dark in there, you come out, and you’re blinded,” said Cathy Boker.
Boker said she switches between her prescription sunglasses and her prescription glasses while she’s driving in and out of the tunnels.
New drivers said the transition is dangerous.
“As a new driver, that’s kind of scary for me, because they’re suddenly braking, even though there’s no problem ahead,” said Jared Walker.
Drivers discussing the issue on Reddit said they feel traffic flow is better on overcast days. They asked why tunnel lighting couldn’t be made brighter.
The Washington Department of Transportation told KIRO 7, their improvements will actually make tunnel lighting 50 percent brighter by early 2017.
They won’t be LED lights, because a WSDOT spokesperson said LEDs have not been tested in tunnel environments yet. They will be high pressure sodium bulbs.
Mark Bandy, an urban corridors traffic engineer for WSDOT said the current lighting system was installed in the late 1980s and early 1990s.
“Designed into it is something called a photocell that measures the outside light, and automatically adjusts the light levels,” Bandy said.
Now, brighter lights will be installed along with reflective surfaces that will distribute light more evenly throughout the tunnels.
While Bandy said this will help make the experience more comfortable for drivers, people will still need to adjust from dark to light.
“It’s just part of the nature of having those wonderful, bright days in Seattle,” he said.
Bandy said the state Route 99 tunnel construction will have brand new lighting systems, and the part of I-5 that goes underneath the convention center downtown does not currently need any lighting adjustment.
KIRO
