Interstate 405 Washington

A short cut and cover tunnel is located on southbound Interstate 405 just prior to the interchange with Interstate 90. Photo taken 08/31/06.

Routing

Interstate 405 provides a bypass to the east of Seattle, connecting with several major suburbs on the east shore of Lake Washington. The freeway is the most direct route to Redmond, home of Microsoft, via the Washington 520 freeway. As a result of growth in the greater Seattle area, Interstate 405 carries significant traffic volume, almost on a level like its sibling in California, albeit with fewer lanes. To alleviate some of this congestion, a second north-south freeway is being considered for the eastern suburbs of Seattle, dubbed as Interstate 605 by some. It remains unclear if this new highway will be constructed.

High Priority Corridor

Interstate 405 is part of High Priority Corridor 35: FAST Corridor.

History

Interstate 405 began as Washington 405 with its first segment running between Renton and Tukwilla. Its first portion opened in September 1965, Washington 405 was redesignated Interstate 405 with its completion by 1971.1

Highway Guides

Southern Terminus - Interstate 5 - Tukwila, Washington
Perspective from Interstate 405 south
Interstate 405 south comes to an end at this junction with Interstate 5 and Washington 518. The left lanes transition directly onto Washington 518, while the right lanes exit onto northbound Interstate 5 toward downtown Seattle. Photo taken by Chris Elbert (03/03/06).
The last ramp along southbound Interstate 405 is the connection to Interstate 5 south. Unlike the north end of Interstate 405, there are no end shields present here. Washington 518 west begins at this point for the remainder of the freeway route to SeaTac and Burien. Photo taken 08/30/06.
Perspective from Washington 518 east
Traffic on Washington 518 dramatically increases after the airport interchange. Next up is the exit to Southcenter Mall, followed by connections to Interstate 5 north to Seattle and south to Tacoma and Olympia. Photo taken 08/29/06.
A button copy exit sign is in use for the Southcenter Mall (51st Avenue South) exit. The next exits are for Interstate 5 south and north. Photo taken 08/29/06.
The left lane exits onto northbound Interstate 5 to Seattle. Both main lanes continue east onto northbound Interstate 405 to Renton. The right lane exits onto southbound Interstate 5 to Tacoma. Photo taken 08/29/06.
Perspective from Interstate 5 north
After the off-ramp to Exit 152 (South 188th Street/Orillia Road South), northbound Interstate 5 next approaches Exit 153, Southcenter; Exit 154A, Washington 518 west to Washington 509 (Sea-Tac International Airport and Burien), and Exit 154B, Interstate 405 north to Renton. Photo taken 08/29/06.
A second set of overheads is posted shortly thereafter. The right lane becomes exit only for both Exit 153, Southcenter and Exit 154B, Interstate 405 north to Renton. The number three lane connects to Washington 518 west to the airport and Burien. A variable message sign is located on the same sign bridge. Photo taken 08/29/06.
Northbound Interstate 5 reaches Exit 153, Southcenter. The next interchange is Exits 154A-B, Washington 518 west to Burien and Sea-Tac International Airport and Interstate 405 north to Renton. Interstate 405 bypasses downtown Seattle to the east of the city center, but its narrow roadway limits its capacity. Daily traffic jams on Interstate 405 are common. Photo taken 08/29/06.
Passing under the Southcenter Parkway overpass in Tukwila, the right two lanes immediately transition onto northbound Interstate 405 and westbound Washington 518. A carpool/high occupancy vehicle lane forms on the left to allow those vehicles to bypass the interchange. Three main lanes carry Interstate 5 through this interchange. Photo taken 08/29/06.
Now on the transition ramp, the right lane connects to northbound Interstate 405, while the left lane connects to Washington 518 west to Sea-Tac International Airport, Burien, and the Washington 509 freeway. Photo taken 08/29/06.
Perspective from Interstate 5 south
The first appearance of Interstate 405 south is found after Exit 156, Interurban Avenue. The next exit is Exits 154B-A, Washington 518 west to the airport and Interstate 405 north to Renton and Bellevue. Photo taken 08/30/06.
This set of signs, found immediately after traffic from Washington 599 south merges onto Interstate 5 south, advises of the pending interchange with Interstate 405 north and Washington 518 west. Note the left exit to northbound Interstate 405 (Exit 154A). Photo taken 08/30/06.
The right two lanes exit first to Exit 154B, Washington 518 west to Southcenter Mall, Washington 99, Sea-Tac International Airport, Washington 509, and Burien. The next exit connects to Interstate 405 north to Renton (Exit 154A). Photo taken 08/30/06.
After the Interstate 5 south high occupancy vehicle bypass lane separates from the Interstate 405 north high occupancy vehicle lane, the left lane prepares to exit onto Interstate 405 north. This interchange marks the southern terminus of Interstate 405 as well as the eastern terminus of Washington 518. Photo taken 08/30/06.
Northern Terminus - Interstate 5 - Alderwood Manor
Perspective from Interstate 405 north
A few miles after the Washington 527 interchange, northbound Interstate 405 approaches its junction with Interstate 5. The left two lanes (inclusive of the former carpool/high occupancy vehicle lane) transition directly onto the Washington 525 freeway spur, which travels northwest toward Washington 99 and downgrades to a regular highway en route to Mukilteo. Note the northbound control city of Vancouver, B.C. and southbound control city of Seattle and destination city of Lynwood. Photo taken 08/29/06.
The right lane becomes exit only for the connection to northbound Interstate 5 to Everett and Vancouver, B.C. The interchange is visible in the distance. Photo taken 08/29/06.
Continuing northwest, Interstate 405 reaches the ramp for Interstate 5 north to Everett and Vancouver, B.C. (two-lane exit). The remaining right lane will connect to southbound Interstate 5. The left two lanes continue north onto Washington 525. Photo taken 08/29/06.
The right lane drops at the connection to southbound Interstate 5 to Lynwood and Seattle. The left two lanes continue onto northbound Washington 525. Photo taken 08/29/06.
An end shield is posted for Interstate 405 along with a begin Washington 525 shield. Photo taken 08/29/06.
Reaching the transition ramp from northbound Interstate 405 to southbound Interstate 5, the left lanes continue onto northbound Washington 525 toward Mukilteo. Photo taken 08/29/06.
Perspective from Washington 525 south
Looking south on Washington 525, the first appearance of the junction with Interstate 5 and Interstate 405 is this roadside sign located a short distance southeast of the Washington 99 interchange. Note that there is no direct connection to northbound Interstate 5. Photo taken 08/29/06.
The next exit is the connection from southbound Washington 525 to southbound Interstate 5 en route to downtown Seattle. Photo taken 08/29/06.
As traffic merges onto southbound Washington 525 from Alderwood Mall Parkway, a new right lane is formed to transfer traffic onto southbound Interstate 5. Photo taken 08/29/06.
Southbound Washington 525 splits, with the left two lanes connecting onto southbound Interstate 405 and the right two lanes exiting onto southbound Interstate 5. This marks the southern terminus of the state route. Photo taken 08/29/06.
As the freeway passes over Interstate 5, a shield assembly announces end Washington 525 and begin Interstate 405. Photo taken 08/29/06.
Perspective from Interstate 5 south
Now traveling south on Interstate 5, the first appearance of Interstate 405 is on this overhead sign, prior to Exit 183 (164th Street SW) and about two miles north of the Interstate 405 junction. Photo taken 08/30/06.
Southbound Interstate 5 reaches Exit 183 (164th Street SW); the next exit is Exit 182, Interstate 405 south to Bellevue and Renton. Photo taken 08/30/06.
The right two lanes will connect to southbound Interstate 405, which ostensibly provides a bypass of Seattle but instead offers a route to Seattle's eastern suburbs. These suburbs have grown tremendously, and Interstate 405 carries a heavy burden created by the additional traffic. Photo taken 08/30/06.
Southbound Interstate 5 reaches Exit 182, Interstate 405 south to Bellevue and Renton. There is no access to Washington 525 north. Photo taken 08/30/06.
Perspective from Interstate 5 north
As northbound Interstate 5 meets 44th Avenue West to Washington 524 in Lynwood (Exit 181A), overhead signs advise of the pending interchange with Interstate 405 south and Washington 525 north (Exit 182). Photo taken 08/30/06.
After Exit 181B (Washington 524/196th Street SW and Alderwood Mall Parkway), northbound Interstate 5 approaches Exit 182, Interstate 405 south and Washington 525 north. Photo taken 08/30/06.
Northbound Interstate 5 reaches Exit 182, Interstate 405 south to Bellevue and Renton and Washington 525 north to Washington 99 and Mukilteo. Photo taken 08/30/06.

Sources:

  1. Interstate 405 (Washington) @ Wikipedia.org.

Page Updated September 26, 2006.

Mileage

State Washington
Mileage 30.30
Cities Renton, Bellevue, Seattle
Junctions I-5, I-90, I-5
Source: December 31, 2017 Interstate Route Log and Finders List
I-405 Washington Annual Average Daily Traffic
State Location AADT Composite Year
Washington Renton 137,000 2002
Washington Bellevue 201,000 2002
Washington Bothell 114,000 2002
Source: 2002 Annual Traffic Report (WSDOT)
Complete Interstate 405 AADT data.
State named trailblazers for Interstates 5 and 405 precede the eastbound on-ramp from Seattle-Tacoma International Airport to Washington 518. Photo taken by Jeff Royston (02/24/06).
SR 509 south at the eastbound on-ramp for SR 518 to Seattle-Tacoma International Airport (SEA) and Interstates 5 and 405. Photo taken by Chris Elbert (03/03/06).