What is the work?
We are replacing two 33-year-old expansion joints that span the width of the highway and the pedestrian/bike path. The joints across the traffic lanes are 82-feet long and weigh nearly 26,000 pounds each. The joints have deteriorated and the synthetic rubber seals are broken allowing water to leak into the joints. This could lead to the expansion joints failing and popping up into traffic creating a safety hazard for the drivers.
Where is the work?
Drivers will begin encountering construction barrels on westbound I-90 near I-405. The interstate will narrow to one lane just before the Bellevue Way interchange. There will be three lanes open across the East Channel Bridge (the westbound lane, a lane joining from Bellevue Way and a third lane joining from I-405). The construction zone will end near East Mercer Way. Residents of Mercer Island will generally not be affected by the construction work since it is taking placing directly east of the island.
When does it start?
We’ll begin closing lanes and ramps starting at 8 p.m. Friday, July 18. Most of the traffic control will be in place by 9:30 p.m. However, the contractor has to do a lot of temporary restriping to make sure drivers can get through safely. That means there will periodic closures of the I-405 ramps to westbound I-90 and the ramp to East Mercer Way. Check our detailed lane and ramp closure web page.
When will it end?
It’s scheduled for completion by 5 a.m. Friday, July 25.
Why is replacing the expansion joints necessary?
Expansion joints are a critical part of a bridge’s infrastructure. The joints allow the bridge to move and flex with changing traffic and weather conditions. Joints that fail can unexpectedly pop up into traffic, resulting in an emergency closure of lanes to replace or repair them. Since no one can plan for a failure and subsequent emergency closure WSDOT wants to replace these joints before they fail and in a manner that allows travelers to plan ahead.
A seven-day closure of all but one lane of westbound I-90 is going to really affect traffic. Why can’t these expansion joints be replaced during overnight closures or on the weekend?
After careful consideration, we determined that due to the nature of the work, it can only be done during one big multi-day closure. We are replacing two expansion joints. Each expansion joint across traffic lanes is 92-feet-long and divided into two pieces:
- This work is difficult and time consuming
There is not enough time in a weekend long closure or nighttime closures to remove the first half of the expansion joints. The joints are embedded six inches into the concrete bridge deck which is 11 inches thick. The concrete must be chipped out, removed, the new joints installed, secured in place, new concrete poured and allowed to cure for at least 12 hours before traffic can drive across it.
Why can’t you do this work during the winter, like between Christmas and New Year’s when people take time off? Isn’t traffic lighter at that time of year compared to summer travel?
The number of vehicles on I-90 is only slightly lower between Christmas and the New Year, when compared to July.
Second, the odds of poor weather are much higher in the winter. Although it is possible to protect newly poured concrete around the expansion joints from the heavy precipitation we often experience in the winter by placing tents over them, we must also consider the increased risk of more severe weather including freezing temperatures, snow and ice. Freezing temperatures would prevent crews from pouring concrete. If we scheduled this work to occur in the winter there is an increased risk of delays or work cancellations. Since we can’t predict when these joints might fail, we need to schedule the replacement work to occur as soon as possible during the best possible conditions which is during summer.
In addition, WSDOT’s first priority is safety for construction and maintenance crews along with drivers. Working in snow and ice increases the risk that workers could slip and fall and suffer an on-the-job injury. We also don’t want to run the risk of a driver losing control in such conditions and crashing into a work zone. For everyone’s safety our maintenance crews concentrate on keeping highways clear. Construction crews usually cancel work during snow and ice for driver and crew safety and to allow maintenance workers to do their jobs.
I’m going to be using I-90 during this work, what kind of backups should I expect?
Nearly 85,000 vehicles travel across the East Channel Bridge each day. Congestion is inevitable. Drivers heading from Issaquah and other communities east of I-405 will encounter significant backups if no one changes their driving routine. Drivers on I-405 will also likely see additional congestion as drivers exiting to westbound I-90 encounter slowdowns that will back up onto I-405.
Will the HOV lanes be open to all?
During stage 1, the HOV lane across the bridge will be under construction. There will be no designated HOV lane during this stage. During stage 2 of the project, when the right lanes are closed, the HOV lanes on the left side of the interstate will be open to all from approximately I-405, across the East Channel Bridge, to East Mercer Way. At that point, I-90 will return to its normal configuration.
Will the express lanes be westbound during this closure?
The express lanes will operate normally during the closure. There may be times when there is additional westbound service due to special events like Sounders and the Bite of Seattle. They won't be westbound 24/7 during the construction work because the westbound entrance comes after the construction zone. That means drivers need to get through the construction zone first, before even reaching that entrance. So having the express lanes going in the westbound direction all the time won't actually help drivers get past the construction.
Are you going to stop tolling SR 520 during the work on I-90?
- SR 520 is one alternative route around the closure and there are other options to get around Lake Washington. This closure will affect many Seattle-area highways.
- We provided drivers almost three weeks notice, to plan ahead so they can make alternate plans when I-90 is reduced to one lane.
- Toll revenue provides $1.2 billion in funding to replace the SR 520 current bridge. WSDOT and the Washington State Transportation Commission (WSTC) estimate the state would lose $1.3 million if tolls were lifted. We have to ensure the tolls are generating enough revenue to cover debt payments. This is achieved by applying the tolls fairly and consistently. The WSTC sets the rates and exemptions to the rates. There is no exemption for construction lane closures on I-90.
- We only waive tolls if a driver is already on SR 520 and they contact us to let us know they had to use the bridge as directed by law enforcement during an emergency.
If I have to take SR 520 during the closure, what are the toll rates and how can I set up an account?
Toll rates vary by time of day and on weekends. The rates are available on the Good to Go! SR 520 Bridge Toll rate website.
There are different options to pay the toll. Drivers can obtain a Good to Go! pass, set up a short term account, or pay by mail to just name a few. Check the different options by visiting the bridge tolling website and select the one that’s best for you.
I use the pedestrian/bike trail frequently. Will that be closed?
The pedestrian/bike trail is not closed. However, the 10 foot-long expansions joints under the pedestrian/bike path will also be replaced.
This work will likely begin the week of July 27, after the highway expansion joints are replaced. The ped/bike path work will occur nightly from 10 p.m. to 5 a.m. The path will not be completely closed during the work, however users will have to stop and wait and wait for a flagger to allow them to continue or follow an escort through the work zone. No work is scheduled to occur between 5 a.m. and 10 p.m.
Most evening and overnight users will only experience delays of five minutes or less. At all times, trail users should be prepared for steel plates across the path and use caution while crossing the plates. The work on the bike path is expected to take approximately ten days to complete.
How many other joints on I-90 need to be replaced?
There are no other expansion joints on I-90 scheduled for replacement at this time. However, WSDOT’s highways are aging and our crews monitor the expansion joints on all our bridges very closely to look for any in need of repairs.