Listening to what the numbers tell us – SR 9/SR 204 roundabout to be rechannelized

 We listen carefully to what our highways tell us.

Though the roads obviously can’t talk, we hear what they’re saying through reports from drivers and community partners who use the roads on a daily basis. We watch with a careful eye, noting how traffic behaves. And, perhaps most importantly, we dig into data to find out if changes we’ve made have the desired effect.

When the numbers show we can still make improvements, our traffic engineers dig in to figure out how. We don’t have an “our way or the highway” mentality – at WSDOT, our way IS ensuring the highway is operating safely and efficiently.

A great example of this will happen Saturday night, Aug. 22, in Lake Stevens.

In 2023, we opened two multi-lane roundabouts on SR 9 in Lake Stevens to help reduce serious injury and fatal crashes and improve traffic flow through the corridor.

In summer 2023, we built two multi-lane roundabouts along State Route 9 in the heart of the busy Frontier Village retail area. These roundabouts were part of a seven-year, $69 million effort working with the community to reduce the potential for serious injury and fatal crashes in the area, limit SR 9 congestion, provide better access to area businesses and improve travel through the area for people walking, biking, taking transit and driving.

Along with the SR 9 roundabouts at SR 204 and Vernon Road, the project added smaller roundabouts at Vernon Road’s intersections with North Davies Road and 91st Avenue Northeast, plus new sidewalks and bike paths.

Then we watched, listened and analyzed to see if the new roundabouts were working as intended.

Digging into the numbers

We’ve fielded concerns from people using the new roundabouts and remained in contact with Lake Stevens officials since the roundabout opened. But it usually takes about three years of post-construction data to see how well a new intersection is working.

Now that we nearly have three full years of data, we have a better picture of how they’ve been performing. Overall, the data showed that collision numbers have decreased since the roundabouts opened. After averaging 16.3 crashes per month the first year after major construction finished (July 2023 through June 2024), that number was down to about 12 collisions per month during the most recent full year since the roundabout opened (July 2025 through June 2026, though that number could change slightly as the most recent collision data is finalized).

While this trend is promising, our engineers developed ideas for further improvement at the roundabout by targeting the locations where crashes are occurring the most.

Chart shows location of crashes entering the SR 9/SR 204 roundabout from the east and the west from July 2023 through June 2026. Safety Disclaimer and Subject Figure: Under 23 U.S. Code § 148 and 23 U.S. Code § 407, safety data, reports, surveys, schedules, lists compiled or collected for the purpose of identifying, evaluating, or planning the safety enhancement of potential crash sites, hazardous roadway conditions, or railway-highway crossings are not subject to discovery or admitted into evidence in a Federal or State court proceeding or considered for other purposes in any action for damages arising from any occurrence at a location mentioned or addressed in such reports, surveys, schedules, lists, or data.

Finding areas for improvement

Looking closer at the numbers, our engineers found that about 86% of the crashes since July 2023 related to the two new roundabouts on SR 9 (419 of 490 crashes) happened at the SR 9/SR 204 intersection.

Drilling even deeper into the crash data at the SR 9/SR 204 roundabout, we found more than 50% of all the reported crashes happened on the SR 204 approach on the west side of the intersection and the Seventh Place Northeast approach to the east.

It is in those two areas where we will focus on making improvements.

WSDOT plans to make four lane striping modifications to the SR 9/SR 204 roundabout in Lake Stevens to help create simpler decisions for drivers.

The solution: Making it simpler

After identifying these collision trends, our traffic engineers set out to find solutions. Turns out, we think the easiest way to reduce crashes is to … well, make things easier.

We plan to make four striping modifications to the SR 9/SR 204 roundabout that we believe will create simpler decisions for drivers and, therefore, reduce chances for crashes. We plan to use lane markings to rechannelize parts of the roundabout by:

1. Removing one of the circulating lanes between the westbound Seventh Place Northeast and eastbound SR 204 approaches.
2. Removing one southbound SR 9 lane entering and exiting the roundabout.
3. Removing one westbound Seventh Place Northeast lane approaching the roundabout.
4. Making minor modifications to the striping on eastbound SR 204 lanes approaching the roundabout.

Not only will these changes create easier decisions for drivers, they also will reduce the number of potential conflict points between vehicles entering and circulating in the roundabout. It also right-sizes the intersection’s number of lanes to current traffic volumes, and it will calm eastbound, westbound and southbound traffic as it approaches the intersection.

Taking away a southbound lane on SR 9 could create more delays than drivers currently see. But we expect these changes will continue to reduce the number of collisions that occur at this busy intersection.

WSDOT will rechannel the SR 9/SR 204 roundabout in Lake Stevens Saturday night, Aug. 22, to reduce the number of places cars could come into conflict with each other and make decisions easier for drivers.

So, what’s next?

Unfortunately, the current pavement markings were not made in pencil, so making the adjustments will take a nighttime closure of the roundabout on Saturday night, Aug. 22. From 8 p.m. Saturday, Aug. 22, to 6 a.m. Sunday, Aug. 23, we will fully close the intersection so that we can remove the old pavement markings, install the new ones and make the SR 9/SR 204 roundabout easier to use. This work requires dry weather and may be rescheduled if rain is forecast.

During this closure, access will remain open to local businesses, but through traffic should detour using Market Place and Lundeen Parkway.

After the new pavement markings are installed, our traffic engineers will continue to monitor the intersection, making sure the changes we’ve made have the desired effect.

As our rechannelization efforts in Lake Stevens show, that’s not an empty promise – we listen to what our highways and the people who use them tell us.