By: Lauren Penning
UPDATE - Nov. 14, 2025: This post has been updated to reflect the new anticipated open date of the northbound I-405 ramp and signal turn on to Nov. 24. Also, when this new traffic configuration opens, there will be an additional lane added to the northbound I-405 ramp to eastbound SR 522 to address congestion for drivers headed to Woodinville.
ORIGINAL: If you drive on State Route 522 near the I-405 Interchange in Bothell, get ready — some big changes are coming your way! Crews are making great progress on the I-405/Brickyard to SR 527 Improvement Project, and the next step is opening a new ramp and traffic signals to help make room for future improvements.
So far at the interchange, crews have built about 3,500 feet of walls along the hillside to support the I-405 expansion and the new northbound off-ramp to SR 522.
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| Construction progress on the new northbound I-405 off-ramp to SR 522 in October 2025. The ramp will carry traffic headed to eastbound and westbound SR 522. |
What’s happening soon
Crews are about to turn on two new traffic signals on SR 522 and move traffic onto the new northbound off-ramp. Once traffic switches over, they’ll remove the old ramps and open up space in the middle of the interchange. Later on, that space will be used to add express toll lanes (ETLs) and new direct access ramps in both directions.
What drivers should know
We are almost ready to turn on the traffic signals. Crews need good weather to complete the remaining ramp build and striping to make the traffic switch as early as Nov. 24. Keep an eye out for new signs, lane lines, and traffic signals — things will look a little different!
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| Crews will add traffic signals at the I-405/SR522 interchange at two new intersections between Bothell and Woodinville. |
How the new setup will work
If you’re coming from southbound I-405 to eastbound SR 522, you’ll turn right at a new traffic signal instead of just merging into eastbound SR 522 traffic.
- If you’re heading from eastbound SR 522 to northbound I-405, you’ll now turn left at a new traffic signal instead of using the old loop ramp.
- Drivers going from northbound I-405 to westbound SR 522 will also turn left at a new signal — replacing the old flyover ramp.
- If you’re going from northbound I-405 to eastbound SR 522, you’ll use the new ramp but still merge with traffic like you do now.
- For drivers who experience congestion heading east to Woodinville, when the new northbound ramp opens there will be an additional lane on the ramp heading eastbound to SR 522.
Everything else at the interchange will stay pretty much the same.
Expect slower traffic at first
When the new traffic signals and ramps first open, things might move a little slower while drivers get used to the changes. Also, crews will still be finishing construction, so there will only be two lanes open on eastbound SR 522 and one fewer lane on the northbound off-ramp. Crews will focus on building out the roadway and ramp in the next few weeks. This will add capacity so drivers will see an improvement soon.
Once the full project is done in 2028, there will be three traffic signals along SR 522. The third and final signal will connect traffic directly to the new express toll lanes.
Why add traffic signals?
It might seem strange to add signals near a freeway, but this design actually helps save budget and time. This design configuration allows the project to keep much of the existing bridges and roadway helping to minimize cost. The decision was made after many discussions about tradeoffs and close coordination with our partners including the City of Bothell and Sound Transit.
The new signals will be timed to work together, so traffic should keep moving with very little waiting. Even during rush hour, we expect the new setup to add only about a minute to your trip on SR 522.
We know this is a big change, but it’s a good one! Once everything’s complete, the improvements will make travel more efficient for drivers, transit riders, and everyone moving through the area.
What’s coming next
Looking ahead, in January 2026, crews plan to remove the old flyover and loop ramps. That work will require two weekend closures of SR 522 and two weekend closures of I-405 near the interchange. We’ll share more updates as those dates get closer.
30 comments:
Since this will punish Kenmore and Bothell, can someone at least fix those two enormous sunken grates that are right in the wheel path on the 527 to NB I-405 on-ramp? Those have been like that for at least 11 years, and I'd guess have caused millions in wear & tear to cars that hit them. The toll lanes were supposed to pay for I-405 maintenance, yet that on-ramp.has long been neglected. It is even worse now that the two on-ramp labes were narrowed, as people in the know try to avoid them.
This is so unfathomably stupid. And you know it is, because you're already getting defensive in the article. The 522 is the only east-west route around the lake. At a time when you should be working on getting rid of *all* the lights on the 522 to improve traffic throughput you instead decide to ADD TWO MORE. All the work on the 85th interchange indicates that some people understand why passive interchanges are necessary, but clearly that information was not available to the idiots designing this project. I sincerely hope that you have a plan in place to replace these lights with roundabouts and that the people who designed this project are put on PIP, if not outright fired.
Wait, so this so called “improvement” to SR522 will actually add three traffic lights in the distance of about 1/2 mile, and by your own admission “…will about a minute…”?
Isn’t, by definition, the addition of time in a journey make it less efficient?
This seems like an ill thought solution to a problem that didn’t exist. I look forward to seeing cars block the intersection (as the do at 520/SR202 interchange) grinding the junction a halt. A roundabout would have been a better solution; they are scientifically demonstrated to yield the highest traffic throughput at the lowest crash incident rate.
Seems this implementation was optimized for budget, rather than for traffic flow.
Roundabouts are cheaper to build and muuuuuuch cheaper to maintain, so not optimized for budget either.
Expect slower traffic at first.
No, it will permanently be slower. You have added full stops to traffic that was previously, by design, flowing traffic. Those flyovers for NB405 to WB 522 was the most genius thing I have seen WSDOT come up with. And then they rip it out and set us back 20 years to when this plan was probably approved.
So what happens when traffic incidents increase in this area? How many people will get killed before you go back to the drawing board?
I say it every time I see another one of your horribly designed plans, go talk to other states like Utah who have WAY better infrastructure and planned well in advance of population bursts.
I don't believe civil engineers are this stupid, I think corporate shenanigans and state and local restrictions have much more to do with this. How do we make it stop?
After reviewing the proposal again, I’m still struggling to understand the practical benefit for drivers. As a transit-oriented project, I appreciate the intention; this corridor is aging and was built for a very different population than it serves today. However, as someone who drives this route regularly for both work and personal travel, I believe the current design will likely need to be reconsidered after implementation.
This roadway is a critical connector for Woodinville, Snohomish, and Monroe residents accessing the 405, areas that are predominantly car-dependent. The new layout relies heavily on motorists demonstrating highly efficient and consistent driving behavior, yet current traffic patterns in Washington suggest that this assumption is unrealistic. The projected one-minute delay is also severely understated; based on existing congestion, the increase will likely be significantly higher.
I agree with others who anticipate that this design may ultimately need to be replaced with a roundabout or another solution better suited to high-volume driver traffic. While I understand that reducing car dependency is a policy priority, it feels as though drivers’ needs and on-the-ground experience are being overlooked. Involving more individuals with real driving expertise in these planning processes could lead to infrastructure that is both safer and genuinely more efficient for all users, including transit riders, cyclists, and pedestrians, without disproportionately burdening those who rely on their vehicles.
So you have spent millions of dollars "improving" the road and successfully added an extra minute to peoples journey times - why didn't you just spend the money making SR 522 a two lane highway all the way to Monroe and eliminate the traffic lights at Paradise Lake road.
I’m shocked that WSDOT would put signals on a high speed limited access highway. Having worked at WSDOT 10 years ago, I’m disappointed. It looks like the traffic engineers and exec mgmt I knew have all left the agency. While I’m certain a few lights saved quite a few million dollars, the long term effect on traffic and will far outweigh the savings. Just a bad design. I hope I’m wrong.
MarkL, thank you for your comment. The project team is looking into how to address this issue going forward.
Barefoot Lance, this design decision was made after many discussions about tradeoffs and is necessary to enable improvements including new direct access ramps to the express toll lanes (ETLs), infrastructure to support Stride BRT, and the addition of another ETL lane. This design configuration allows the project to keep much of the existing bridges and roadway helping to minimize cost.
We acknowledge that this will be a change for drivers that use the interchange. However, our traffic analysis shows that when implemented, the signals will add approximately one additional minute to SR 522 travel during peak hours. To help minimize delay and keep traffic flowing, we will time the signals to work together so that vehicles can move efficiently through the interchange with minimal stoppage time.
While adding the traffic signals requires modifications to the existing configuration, the overall benefits of transit connectivity and improved traffic flow on I-405 are significant. We know that there is traffic congestion at this interchange today. The project is adding an additional lane to the northbound I-405 ramp to eastbound SR 522 to increase capacity and help ease congestion.
Ceesar, thank you for your comments. While budget was certainly a factor in this decision, it also makes the most sense for the traffic flow needed at the interchange to enable improvements to ease overall congestion. As shared, we will work to time the signals to work together to minimize delay.
Barefoot Lance, roundabouts were considered for this interchange but space constraints including the location of the trail, river and existing interchange columns were all issues that make building roundabouts here not possible. Looking at all the options and weighing the efficiency gained by enabling the improvements, adding signals was the best option at this interchange.
And safer too.
This is clearly just another underhanded attempt by WSDOT to penalize drivers.
The cynic in me could believe this whole scheme is a method to extract more tax (in the form of ETL usage fees) from drivers; who are already paying the 3rd highest gas tax in the nation, for very little return - and in fact - schemes like this will have a detrimental affect (according to your own analysis).
Especially when the last study contracted by WSDOT found that the ETL lanes DID NOT deliver on or meet the Federally mandated requirements for use of an ETL system
https://conservancy.umn.edu/server/api/core/bitstreams/5e0a26dc-9d72-4c74-8bc6-e242ef1bd72a/content
And how much more efficient would it be to use roundabouts? How much cheaper would it have been to implement? How much cheaper would it be for annual costs? How well will these lights work when the power goes out (as it did for multiple consecutive days last winter)? I stand by my "unfathomably stupid" comment.
Wow! WHO took over WSDOT? WHERE did they come from? This is NOT SMART thinking! Do they even drive?
It COMPLETELY WAS ABOUT MONEY! Again WSDOT project planners focus on completing their goals for their personal BONUSES while scarificing the PEOPLES time. Our time is valuable!
This IS DUMB! STOP trying to explain it away!
SERIOUSLY FIRE THE DECISION MAKER!
Adding lights SHOULD NEVER EVEN be considered. This reeks of someone from the East Coast where this is considered acceptable. CA is REMOVING lights, not adding them! Think ahead NOT quick fixes on the cheap.
Do it RIGHT the FIRST time!
Instead of KEEPING the old flyovers WHICH WORKED! ADD two more to supplement. One could be buses or HOT lanes to MAKE MONEY. Why TRASH the flyovers??? Use them!
You all MUST stop drinking your own Koolaid!
I spoke with WADOT at the community meeting years ago when this plan was being created. They already had a plan and there was nothing UW Bothell or Woodinville could say to stop this. 8-10 years ago you added the newer braided ramp to get onto I-405 at Juanita-Woodinville way. That has been a nightmare backing cars onto I-405. Not your going to stop vehicles going east bound towards Woodinville or Monroe. You’re going to stop 30k+ cars going into Bothell and you’re saying 1 minute? The repercussions will be a domino effect that will teleport traffic stops onto I-405. When toll lanes were added to I-405 the data was incorrect and you had to open a shoulder for evening traffic. Your data will be wrong again, but it’ll be too late. You’re spending $1 billion and tearing down direct access ramps. This is horrible, who ever designed this.
This reflects my thoughts as well. Love the idea of a transit corridor. This, however, does not sound well thought out. It really sounds like the overriding priority was putting in ramps for the hov lanes.
It’s certainly a nice to have, but at this level of disruption, I don’t know. I’d like to see the analysis and the final design renderings with the stride lanes, the hov ramps, etc. that might help me understand the space constraints.
Right now I’m just scratching my head like everyone else.
PLEASE leave the Bothell flyover!!!! It’s mind blowing that you’re removing this. Traffic here is already abominable. Those traveling west shouldn’t have to suffer with the 522 E traffic. Bothell and Kenmore residents will suffer so much with this plan. It seriously has me upset. Please leave the flyover alone!
It's hard to tell from the limited diagrams, but I'm anticipating that the one minute delay to turn from WB 522 to NB I-405 will back up during morning rush hour to the point where it causes a 5 to 10 minute delay to continue on 522 into Bothell, and maybe even to the point the ramp to SB I-405 is impacted or even blocked. I hope your traffic studies showed otherwise, but unfortunately they were probably done by the same "engineers" that said that the EB 522 evening rush hour backups were caused by the highway ending in Monroe, not the traffic light at Paradise Lake Rd.! Clearly not folks who have to travel it everyday.
I know you say that you modeled this extensively, but as an engineer, I am highly skeptical of that claim. I drive this stretch of road every week. A toddler can predict what is going to happen with the SB405->EB522 Ramp+Signal without any modeling at all. The back-ups on to SB405 will be of biblical proportions.
Then we need to discuss NB405 to WB522. This interchange complex already creates multi-mile long backups during rush hour that extend far south on NB405, and your solution is "Let's make those backups ... even longer?" By forcing those cars to wait you at the light they will back up into the EB522 split, which will force them on to the NB405-522 off ramp because there simply isn't enough space to build the holding capacity required to handle the volume.
This is a simple throughput math problem, no modelling required. How many cars attempt to use the flyover per minute during rush hour today? That is how many cars will have to wait in the holding area for each minute the light is Red before spilling into the split. And this assumes the light permissively allows the holding area to drain completely, which we know it cannot because the impact on the west signal would create catastrophic backups for SB405.
I hate roundabouts, but nobody will die from moving the river or the trail to build roundabouts. Roundabouts would keep traffic flowing and reduce backup related fatalities. So now we the taxpayers will have to pay again to fix this properly when this engineering failure becomes unmanageable.
522 WB is backed up from 405 to HWY 9 in the mornings currently, so how is adding a stop light going to "make travel more efficient"? WSDOT has done some questionable things, but spending money to INCREASE travel time is just unacceptable.
I’m trying to figure out how going through two stoplights from southbound i405 to eastbound sr522 is going to be anywhere near as efficient as the old exit and merge. Or taking 522 through Bothell eastbound still has two new stoplights.
I mainly use this intersection while driving to Ski, and the old layout made a lot of sense, whether coming from Seattle or Bellevue.
Horrible. Why would you remove the 405-N bridge to 522-W just to reroute it through a stop light? The eastbound bridge is the only spot experiencing traffic. That puts a terrible strain on 522 travelers. This seems entirely purposed towards our express lanes and making them more appealing. Fire everyone, WSDOT continues to take steps backwards.
Probably way too late but I would have at least tried to preserve the north 405 to east bound 522 flyover as an exit from the toll lanes at a minimum. I would think you could build a crossover bridge to position traffic correctly if necessary. It's done this way at the 405 to I90 interchange. I say use some of that toll money for that... instead of knocking down a perfectly good flyover. You can keep your lights for the non-toll exit, but save the flyover!
*correction* NB 405 to west bound 522 flyover...
I actually went and met with the project team many years ago now. Many of your comments above were put on the table as well as proposing a design that was meant to meet the goals of widening 405 while also improving local traffic flow and maintaining the SR 522 freeway and system interchange.
1) adding a new east-west connection at approximately NE 185th St to meet Campus Pkwy on the western limit and 120th Ave NE on the eastern limit. This new connection could have been used for the direct access ramps to/from I-405. A new transit center could have been built just east of 405 next to the Home Depot.
2) Rebuild the I-405 & SR 522 interchange to a similar configuration that it has been. The northbound off ramps to both east and west 522 would need to be relocated and rebuilt. The N-W flyover would have to be relocated to allow for I-405 widening. The new N-E ramp would still have a second lane added.
3) allowing for a future high speed direct access HOV flyover for the 405N to 522E and 522W to 405S movements connecting to the center lanes for both 405 and 522. Add HOV lanes on 522 initially between 405 and SR 9.
Of course there is always the negative impacts on the wetlands. However it felt like the design I had laid out while it would impact wetlands, should have been fairly minimal.
All of this was part of a grand idea that I had envisioned of a “NE Relief corridor” along SR 522 between 405 and Maltby, then turning north and meeting SR 9 near SR 96 then following SR 9 northward connecting back to I-5 somewhere near Arlington. Might be a far fetched concept however it is a concept that would have helped easy traffic along I-5 and provide a reasonable alternative.
El Jefe, in a blog post earlier this year we published a rendering of the final configuration with all three traffic signals. This design concept is also available on the project website under "maps & drawings."
You should put lights on the merging lanes from wesbound 522 merging onto Southbound 405. Because so many cars are dropped onto 405 it ALWAYS causes traffic jams because drivers cannot merge, and merge fast enough. MERGING is the cause of ALL TRAFFIC JAMS, it needs to be tamped down.
This will be like the infamous North Bend stop light before the I-90 bypass was built. Only infinitely worse. To avoid the hour plus delays this will cause with mile long backups behind these stupid stop lights, traffic will be leaving I-405 at every exit within 10 miles of this interchange. 116th down to Juanita and then north on 100th or past the park and up the curly road that is Juanita Drive. These are two lane roads with low speed limits and stop lights. You took an interchange that was functional, spent years on a construction project that seems to last forever, to ADD stop lights, and to destroy a BOUGHT AND PAID FOR flyover ramp.
It would have been better to have left this interchange the way it was and spent the money resurfacing the shock absorber exerciser that is I-5 between downtown Seattle and Mountlake Terrace.
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