Thursday, June 6, 2019

Like a car needs an oil change and tune-up, Seattle’s SR 99 tunnel also needs regular checkups

Full overnight closure of the tunnel happening Friday night to Saturday morning

By Thomas Charlson

Many of us have experienced car maintenance issues. When my car broke down last year, I learned the hard way about the importance of getting regular tune-ups to save money on repairs in the long run. In this case, I had the spark plugs replaced earlier in the year but continued to have engine problems. After a series of other car repairs, I found out that they were the wrong brand of spark plugs for my car model.

Similar to maintaining a vehicle, we need to give Seattle’s new SR 99 tunnel a regular checkup. That means monthly closures to ensure the tunnel systems are running smoothly and to keep up with the warranties. This helps us avoid problems like I experienced with my car.
Prior to opening the tunnel, we washed the walls. This vehicle is also used for regular maintenance cleanings.

Full tunnel closure June 7-8
While these maintenance closures of the SR 99 tunnel will typically be in one direction, the closure coming up this weekend – from 10 p.m. Friday, June 7 until 8 a.m. Saturday, June 8 – will be a little different.

This time, we need to update the fire control system software. To do that, we need to turn off the fire control system. For the safety of the public, that will require a full closure of the tunnel in both directions. People who use the northbound SR 99 tunnel will be diverted onto the northbound off-ramp to South Dearborn Street and Alaskan Way South.
Crews use lift trucks to access the cameras, signs and lighting in the SR 99 tunnel.

Past and future maintenance closures
Monthly maintenance closures for the tunnel began in April and will usually close just one direction of the tunnel. Our goal is to keep disruptions at a minimum, so we combine all our maintenance operations into one closure. But instead of changing spark plugs and rotating tires, we wash the tunnel walls, sweep the roadway surface, and inspect fire detection systems, cameras, lights and overhead signs.

Crews check the jet fans used to push fresh air into the tunnel.
In July, we’ll resume our regular schedule and close the northbound lanes. To stay updated on SR 99 maintenance closures, you can always use the following tools to get the latest info: