Drivers heading from Seattle to Bellevue on I-90 need to be prepared for something they likely have never faced.

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There are two lanes of traffic are open in the south bore tunnel on the right as they head across Lake Washington. There has been one lane in that tunnel since the westbound tunnel opened in 1989.

Not to worry, the south tunnel is the exact same size as the north tunnel. It is tight, but nothing drivers haven’t experienced before.

Two lanes will remain open in the left tunnel, but one of those lanes is closed just after the Mount Baker Tunnel — it will eventually become the HOV lane. That is forcing drivers to merge approximately two-thirds of the way across the bridge.

Travis Phelps with the Washington State Department of Transportation said drivers need to be ready for this change.

“There’s going to be a little bit of a learning curve for getting into these HOV lanes and when to merge out,” he said. “We’ll be watching that.”

Drivers in both directions need to be ready for lane configurations changing on a daily basis as crews re-stripe 14 miles over the next month.

“Striping changes could be coming through at any moment after these weekend closures,” Phelps said. “Your roadway is going to change and be in transition for the next month or so.”

Phelps said crews have a lot of work left to do inside the I-90 tunnels to get them ready, especially all the new life-safety systems and fans.

“To test this stuff, you basically have to shut it down,” he said. “You can’t have cars going through there, and dropping foam and sprinklers and messing with lights, that would confuse drivers. We want to get that done before we have to turn over the center roadway.

“This is kind of that crunch-time to make sure it’s all running just the way we like it.”

There is a westbound directional closure set for next weekend, and then some occasional nighttime closures to work on striping. That work is weather-dependent, but the state is still targeting June 3 as the day the express lanes go away.

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