Preserving our state highways, one chip seal at a time

By Brian Turner

At the Washington State Department of Transportation, we not only build roads – we maintain them. One of the methods we use is called chip seal. It doesn’t involve any swimming mammals, but it does help keep our highways smooth.

The chip seal projects apply a special protective surface to existing pavement. Basically, we lay down a sticky surface on the road and cover it with small chips of rock. The sticky surface and rocks get pushed into the road by traffic, creating a protective layer. It’s a cost-effective way to extend to life of a roadway.

This summer, our contractor will chip seal on six different sections of highway in Clallam, Grays Harbor, Jefferson and Pierce counties.

Grays Harbor County

• US 101 – Grays Harbor Co Line to South of Lund Road - (6.5 miles)
• US 101 – South of Lund Road to North of SR 107 (4 miles)
• SR 105 – Whalebone Way to SW of Constantine Way (42.97 miles)

Jefferson County

• US 101 – North of Big Quilcene River Bridge to North of Mt Walker Lookout Road (3 miles)

Clallam County

• SR 110 – US 101 to Lapush Road and Mora Spur (10 miles)

Pierce County

• SR 165 – South of Carbon River to South of 112th Street E (3.5 miles)

What to expect

Work is expected to start June 17. The projects will occur at various locations throughout the summer.

Crews will close lanes to perform the work. Typically, only one lane will be available for traffic to alternate in both directions. That means drivers will be taking turns traveling through the work zone, and traffic is guided by pilot cars or flaggers.

The speed limit will be reduced around the clock until a project is complete. The slower travel is not only safer for the people working on the road, but it also reduces the chance of damage to vehicles.

This work will cause travel delays. Travelers will want to plan for additional travel time and remember to bring along lots of extra patience.

Diving in deeper

Like a seal, we love diving deep and exploring. Join us as we explore more about how the chip seal process works:

• Clean Up: First, the road surface gets a cleaning to remove dirt and debris. Cracks might also be filled to create a smooth base.
• Asphalt Shower: A thin layer of hot asphalt or an asphalt emulsion (mixed with water) is sprayed onto the road.
• Rock Shower: While the asphalt is still hot, a layer of crushed rock (chips) is spread evenly on top. These chips are typically three-quarters inch or smaller.
• Roll it in: Rubber-tired rollers press the chips into the asphalt, ensuring a good bond.
• Loose Ends: The asphalt cures in a day or two. Then a sweeper removes any loose chips.

Why we chip seal

Chip seal isn't a magic solution for road repair, but it has several benefits:

• Protects the pavement: It acts as a waterproof barrier, shielding the road base from water damage, which is a major cause of cracks and potholes.
• Safety Benefits: The embedded chips create a textured surface, enhancing traction for vehicles, especially in wet weather. It also provides and anti-glare surface during wet weather.
• Cost-Effective: Compared to a complete road repaving, chip seal is a much more affordable way to extend a road's lifespan by several years.

Not only does chip seal preserve road surfaces, it also improves traveler safety. The protective coat restores traction to prevent skidding, particularly on wet roads. It helps visibility by providing an anti-glare surface during wet weather.

We need your help keeping crews safe

First and most importantly, drive the posted speed limits and don’t drive distracted in work zones. The best thing you can do is slow down in work zones. That makes it less likely that your tires will kick up rocks. Most importantly, it helps keep the workers who are out fixing our roads safe.

Stay informed

To stay informed about chip seal work and all the other construction happening across the state this summer, download the WSDOT app to your smartphone. You can also check out where work zones are on our statewide travel map. Both have real-time travel info.

No matter where you come across our road work, the next time you see a chip-sealed road, know that it's not just a bumpy ride. It's a smart way to keep our roads safe and extend their service life.

This blog is Chip tested – seal approved.