The story behind the Aurora Avenue lane closures

We’re quickly nearing some major lane closures in both directions of SR 99/Aurora Avenue heading into and out of downtown Seattle. Starting Jan. 18 and continuing for several weeks, drivers and bus riders should expect slower commutes and some challenging traffic, which is never welcome news. Why these particular closures now? Please read on.

What is closing?
The inside lane in each direction  of Aurora Avenue North between the Aurora Bridge and just north of Mercer Street will close around the clock  for four to five weeks. In an effort to try to balance traffic as much as possible, we’re opening up the southbound bus-only lane to all traffic during the closure. We recognize that this will be a challenge to everyone, including transit users, but with 37,000 trips southbound daily on that stretch, restricting all passenger vehicles to one lane would back traffic up beyond the Aurora Bridge. That would create even more commuting difficulty for everyone.
An additional lane will close at night and during some weekends to allow construction crews to safely complete their work. When the inside lanes reopen, the right lane of southbound Aurora Avenue North will close for one block near Comstock Street for another two weeks.
Again, we recognize that Aurora Avenue North is already a tight squeeze and we don’t take closing lanes lightly. We’re working with our partners at the City of Seattle and King County Metro to make your trips as smooth as possible. Metro will have extra buses on standby to help maintain schedules but drivers should expect delays, consider alternate routes if possible and use caution if traveling in the transit lane as buses will continue to make all of their stops.
What is the closure for?
During the lane closures, contractor crews building the northern approach to the new SR 99 tunnel will install the foundations for overhead traffic signs that will communicate important information to drivers – similar to the large electronic signs on I-5 and other roads.
Crews will install foundations for a sign structure like this one during the upcoming SR 99 lane closures.
Why do this now for a tunnel that isn’t complete? Great question.
Bertha, the SR 99 tunneling machine, is tunneling again and headed toward downtown Seattle. The sign foundation work has to be done, and we’ve already delayed these closures once. Delaying any more isn’t going to make it any easier.
We’re doing the work in winter because traffic volumes are lower and we can avoid the cascade of sporting events, concerts and other activities that make Seattle’s spring and summer so fun. For northbound and southbound combined, roughly 74,000 vehicles and 36,500 bus riders use the stretch of road between the Aurora Bridge and the Battery Street Tunnel on a daily basis. Congestion grows as the year progresses.
The bottom line? There’s never a good time to close lanes but we chose this time of year to minimize the pain as much as possible. 
Why will it take so long?
These signs require sturdy, concrete-encased pedestals along with communication and power lines and traffic sensors. It’s no small task. We need large drill rigs and specialized crews to complete the work. We also need concrete barriers to keep drivers and workers safe as they share the narrow roadway. 
Yes, we could build the foundations one at a time. But that would simply extend the work into the busier traveling months, running into both the Mariners and Sounders seasons, and wouldn’t be an efficient way to spend taxpayer dollars.
Why not just work at night?
Safety is always our top priority. This work requires us to set up concrete barriers to separate the work area of the traffic. Setting up barriers is a time-consuming process so leaving them in place allows crews to spend more time working, which means a much shorter overall duration for the work. And that means less time drivers and bus riders are stuck in traffic.
What can you do to prepare?
Stay tuned for additional information regarding some of the tools you can use to make your trip as smooth as possible. In the meantime, please start planning now and continue to check out our webpage for traveler tips and more closure information.
As always, we appreciate your patience. We’ll work hard to complete the work as quickly as possible.