information from Washington State Department of Transportation

Closing SR 99 through downtown Seattle for approximately three weeks will cause major disruptions to traffic throughout the region. It’s a challenge we don’t take lightly, and so we’ve spent many months studying and refining our plans to ensure we take the most efficient, least impactful approach.

The results of that effort were recently finalized. The details of the closure plan we shared earlier this fall are largely the same. Mainline SR 99 will close through downtown Seattle for approximately three weeks beginning Friday evening, Jan. 11, 2019. There are, however, a few refinements to the original plan: 

• Effective Dec. 14: Crews will reduce the length of the northbound SR 99 transit lane in SODO by approximately 1,400 feet. This will enable the contractor to repair a dip in the road at that location that would otherwise need to be repaired during the mainline closure. Starting the work early will support access to the SR 99 closure work areas and enable the contractor to focus on other critical work during the closure.
• Effective Dec. 14: Crews will shorten the southbound right-turn lane to Harrison Street and narrow travel lanes on SR 99 near the SR 99 tunnel’s north portal. This will allow safer and better access to work areas and reduce the schedule risks associated with removing a temporary wall that supports the existing highway.
• Jan. 4: The most notable change from the previous sequence is the date of the northbound on-ramp closure near the stadiums. This ramp, which connects approximately 12,500 vehicles each day from South Royal Brougham Way to northbound SR 99, is now scheduled to close on Jan. 4, 2019 – one week earlier than the previously announced date. This additional week will allow the contractor more time to perform critical work (including unburying tunnel on- and off-ramps) that has the potential for some unanticipated challenges, giving crews additional flexibility during the mainline closure. The southbound SR 99 off-ramp to South Atlantic Street near the stadiums will also close as scheduled at this time.

These refinements will reduce the amount of work that would otherwise need to be completed during the mainline closure. As a result, the contractor will be in better position to timely complete work that must be finished prior to tunnel opening. A full look at the closure sequence is available at our #Realign99 page, where you’ll also find resources about how to prepare for the longest major highway closure the Puget Sound region has ever seen.