From WSDOT

The Washington State Department of Transportation is required by the Federal Aviation Administration to close the Interstate 90 floating bridge to drivers, cyclists and pedestrians while the Blue Angels practice for and perform at the Seafair Air Show. The closures are to keep the public and pilots safe and to minimize distractions.

Exactly where and when will I-90 be closed?

The mainlines of I-90 will be closed between I-5 in Seattle and Island Crest Way on Mercer Island:

• Thursday, Aug. 2: 9:45 a.m. – 12:15 p.m.; 1- 2:45 p.m. (practices)
• Friday, Aug. 3:  12:55 – 2:45 p.m. (Seafair Air Show)
• Saturday, Aug. 4 : 12:55 – 2:45 p.m. (Seafair Air Show)
• Sunday, Aug. 5:  12:55 – 2:45 p.m. (Seafair Air Show)

Pedestrian access to I-90: 

The bridge highrises will still be accessible to pedestrians and cyclists. However, no one on foot or bike can travel beyond the highrises up to 30 minutes prior to posted closure times.

Which ramps will be closed?

Several I-90 and I-5 ramps will close 30 minutes to one hour before practice and Seafair Air Show times.

Mercer Island ramps to close:

• West Mercer Way to westbound I-90 (up to 90 minutes beforehand).
• East Mercer Way to westbound I-90 (up to 60 minutes beforehand).
• Eastbound I-90 to West Mercer Way (up to 30 minutes beforehand).
• 76th Avenue to westbound I-90 (up to 30 minutes beforehand).
• Island Crest Way to westbound I-90 (up to 30 minutes beforehand).

Seattle ramps to close up to 30 minutes prior:

• Northbound I-5 to eastbound I-90.
• Southbound I-5 to eastbound I-90.
• Northbound Rainier Avenue South to eastbound I-90.
• Southbound Rainier Avenue South to eastbound I-90.

What specific regulation forces the closure of I-90?

The FAA requires a safety zone around and below the area where the Blue Angels practice and perform. These horizontal and vertical restrictions are in place to protect the public, property and pilots. This zone, also called “the box,” covers part of Lake Washington and the floating bridges – hence the closure. Additionally, keeping drivers off the bridge while the Blue Angels are in the air keeps drivers from being distracted and prevents collisions on the bridge.

Why does the bridge close before the Blue Angels actually perform?

Before each performance the Blue Angels will be in the air, but will not perform specific maneuvers. The bridge closes because it still poses a safety concern.

How will I know when the road is actually closed?

WSDOT will use variable message signs on I-5 and I-90 to countdown to the closures.  We will also use social media such as Twitter to alert travelers. We strongly advise motorists to plan alternate routes in advance. Please do not expect to cross the bridge at the last minute. Congestion and unexpected delays on the roadway may leave you in your car sitting in traffic waiting out the performance.

Will the State Route 520 floating bridge be affected?

The SR 520 floating bridge will remain open to traffic and tolls will be collected according to the rate schedule . Infrequent users of the SR 520 bridge may want to consider setting up a short-term Good To Go! account  for Seafair weekend. Drivers crossing SR 520 should expect heavy traffic, significant delays and plan for additional time to cross the lake.

Who will keep people and vehicles off the roadway during the performance?

WSDOT works with Washington State Patrol to control on-ramps and
off-ramps and keep pedestrians off I-90. The Washington State Patrol will open the roadway as soon as safely possible after the performances are finished. WSDOT’s Incident Response Teams will also patrol I-90, I-405 and SR 520 to keep these alternate routes free of disabled vehicles so traffic will move as freely as possible.

I live on Mercer Island, how will I be affected?

Drivers who need to get around Mercer Island should follow signs for detour routes. Most roads will be open for local access only.

What if I have a medical emergency and I need to get to Harborview Medical Center or Children’s Hospital?

Emergency vehicles will have access to the I-90 center roadway if needed.

Where can I get more information?

Seafair: http://www.seafair.com

or contact us