A crew member works to apply slurry seal on a street in Seattle. Photo: SDOT Blog stats: 1,200 words | 6-minute read
Every year, our community sees the benefits of diligent street maintenance, and 2025 was no exception. Our annual Slurry Seal project, an essential part of maintaining our city streets, has once again provided smoother, safer streets while significantly extending pavement life. With a combination of thoughtful planning, hard work, and community cooperation, this year’s project has been another success.
Here’s a closer look at what we achieved together, the positive impacts on the Seattle community, and how we tackled challenges along the way. This year’s efforts focused on northeast Seattle in the Meadowbrook neighborhood and southeast Seattle near Seward Park.
Check out our quick video to see the work in action!
What is Slurry Seal?
Before we reflect on the accomplishments, let’s briefly talk about what slurry seal is and why it’s so important. Slurry seal is a thin, protective layer applied to roads, kind of like how we apply sunscreen to our skin on sunny days. The material is made up of a mixture of water, asphalt ‘emulsion,’ and fine aggregate (very small pieces of crushed rock and sand). It preserves the pavement, boosts durability, and helps prevent more costly repairs – an investment that saves the City and taxpayers money in the long run.
This preventative maintenance solution smooths road surfaces, fills small cracks, and adds years to a street’s lifespan. It’s a cost-effective approach that helps ensure safe, reliable travel for everyone.
The Numbers Speak for Themselves
This year’s project covered a significant stretch of streets across several neighborhoods in the city. Here are the highlights:
- More than 20 “lane miles” of street resurfaced: With the completion of multiple neighborhoods and arterial streets, we ensured smoother travel and improved experiences for thousands of residents. Lane miles measure a street’s length as well as how many lanes wide it is, not just the distance from point A to point B.
- Hundreds of minor issues resolved: From hairline cracks to slight dips in the pavement, slurry seal tackled a wide range of maintenance problems, protecting roads from further wear and tear.
- 40% more streets treated compared to last year: With in-depth planning and effective delivery, we exceeded our 2024 numbers, improving more streets for more Seattle residents and travelers.
These milestones showcase our ongoing commitment to improving infrastructure and ensuring our street network meets the needs of a growing community.
Please note, crews are working to paint new street markings in some areas, work that is expected to be completed soon.
Benefits to Our City
The benefits of this year’s Slurry Seal project extend far beyond the number of streets resurfaced. Here’s how this initiative is making a difference citywide:
- Smoother, Safer Streets: Residents can now enjoy quieter, safer trips across recently resurfaced areas. By filling cracks and creating a smoother finish, the project has improved traction for vehicles, reducing the risk of crashes.
- Extended Pavement Lifespan: By addressing small issues early, slurry seal extends the lifespan of streets for many years to come. This means fewer disruptions in the future and considerable savings for both the City and taxpayers.
- Eco-Friendly Impact: Preventative maintenance is not only cost-effective, but also environmentally friendly. By prolonging the life of existing streets, we reduce the need for more resource-intensive reconstruction projects. Less material, less waste, and less disruption – it’s a win-win.
Overcoming Weather and Scheduling Challenges
Any large-scale infrastructure project comes with its hurdles, and this year was no different. However, through teamwork and careful planning, we navigated these challenges successfully while prioritizing clear communication and community needs.
In 2025, we scheduled our slurry seal work in mid-August to improve neighborhood streets during a typically drier, warmer part of the year. As with any outdoor project, unexpected rain or other issues can cause changes to our plans.
This year, several days of rain briefly delayed work. To address this, we encouraged residents to sign up for email updates so they could stay informed about any last-minute schedule adjustments. Project crews adjusted shifts and schedules to keep the work moving forward without sacrificing quality.
To help residents stay informed, we provided maps showing exactly where work would be taking place. Only streets highlighted in orange on these maps were selected for treatment. For full details, residents could download the maps directly from our website.
Traffic Management and Community Support
Street closures were necessary to complete the slurry seal process safely. Project team members placed ‘No Parking’ signs up to three days before work began. These signs remained in place until the street fully dried – typically up to eight hours after the slurry seal was applied.
During this period, access to streets and on-street parking was restricted, and vehicles left on the street were subject to be relocated around the corner to remain out of the way of the slurry sealing roadwork. We understand this is an inconvenience and we worked closely with businesses and residents to minimize disruptions.
Clear signage and communication in advance helped keep everyone informed. If streets required work on a scheduled garbage or recycling pick-up day, we coordinated early pickups to ensure vital services continued uninterrupted.
Preparing the Neighborhoods and Ensuring Safety
Residents noticed work crews and equipment arriving before 7 AM, setting up and making the streets ready for treatment. Sweeping and preparation were completed before applying the slurry seal.
We wanted everyone in the community – including pets and children – to stay off the newly sealed surfaces until they reopened for traffic. For streets without sidewalks, the slurry seal was applied only to the road edge. Residents working on private projects that could impact the street were asked to finish the work ahead of our project.
The great thing about this work and the materials we use, is that it only takes a few hours to ‘cure’ to the point that people and cars can use the street again, meaning a relatively short closure of each street. Warmer weather and winds help to speed up this process even more.
Stay Informed
Want to know when your street is up for maintenance or follow other infrastructure projects in Seattle? Stay in the loop, share your feedback, and be part of the collective effort that keeps our community thriving.
You can sign up for email updates and follow us on social media for the latest information.
Thanks for Your Help
A project of this scale can’t succeed without the patience and support of our residents. Thank you for your understanding during street closures, your feedback on improving the process, and your commitment to taking care of the community we all share.
Together, we’ve ensured safer, longer-lasting streets for everyone. Here’s to a smoother ride for years to come!