After drivers adjust to I-90 changes, study suggests travel times will be about the same

As changes come to I-90 to make room for light rail, getting on and off Mercer Island starting next week could be rough.

The express lanes that allowed islanders single-occupancy access between the island and Seattle will close, as traffic shifts to new HOV lanes that are squeezed onto the bridge.

But what happens after the dust settles, when people get used to the changes and steps have been taken to mitigate congestion?

A consultant’s report released in April for Sound Transit suggests I-90 travel times to and from Mercer Island during light rail construction will end up about the same.

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“Long term, there will be very little change in the traffic we see today during construction, and when it’s all complete there will be a slight improvement,” said Rachelle Cunningham of Sound Transit.

The study projects Mercer Island residents who commute to the east side will see their trip home cut by three and a half minutes.

Drivers commuting alone to Seattle will see their travel time rise by two minutes, while those going by carpool or bus will see a two-minute drop.

Mercer Island resident Michael McLeod said he’s not worried about the traffic on I-90, but the traffic on the island.

Solo drivers won’t be able to use the Island Crest Way on-ramp, so they’ll have to find another way to westbound I-90, which could jam the streets in town.

“If the travel time here on the island increases by another 15 to 20 minutes, that’s incredibly unfair,” McLeod said.

Sound Transit and WSDOT say it’s unclear how long the adjustment period will last.

Sound Transit will pay for some traffic mitigation on Mercer Island.

Those measures will be decided after studying the new traffic pattern.