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Surface treatments help keep Salt Lake City roads in good shape by protecting them from water damage and wear. Depending on the road’s condition, these treatments can add years and even decades of life to road segments at a fraction of the cost compared to replacing the road. The Streets Division uses three main types: overlays, slurry seal, and chip seal.

Overlay

An overlay is when we mill down the existing asphalt two inches, and then add a layer of fresh asphalt.

There are streets in Salt Lake City that are in very poor condition that we can no longer do slurry or chip surface treatments on, but they don’t need full depth reconstruction. If nothing is done, these roads will deteriorate rapidly and soon require expensive reconstruction. The new mill & overlay program allows Streets to perform maintenance on these roads and deter or avoid expensive reconstructions entirely. This program brings the streets up to such a condition that they are eligible to receive chip and slurry surface treatments down the road, significantly prolonging the life of the road and saving tax-payer dollars while increasing the quality and safety of our road infrastructure.

Overlays

Overlays take 2 days with the following steps. All roads are selected the prior year through the selection process.

• Notifications are given 24 hours before with date and explanation of tasks for residents and businesses prior to work being conducted.
• “No Parking” signs go up the day before.
• On the day of work, Cartow will relocate any vehicles left on the street to an adjacent area.
• Crews will set out any necessary traffic control signs.
• The road is milled 2″ curb to curb.
• The area is broomed for debris and curb gutters are leaf blown as well as drive approaches.

Paving will take place the following day after milling.

• Traffic control devices are set in the correct locations.
• The area being paved is tacked.
• Crews pave when the asphalt arrives on site.
• The roller will follow the paver to compact the material.
• The material is allowed to cool.
• All traffic control devices are picked up and the area is cleaned.

Slurry seal

• Notifications are given 24 hours with date and explanation of tasks for residents and businesses prior to work being conducted.
• The day before the work, “No Parking” signs are posted.
• On the day of the treatment, Cartow will relocate any vehicles left on the street to an adjacent area.
• The road is closed and cleaned with street sweepers.
• Then, a special truck spreads the slurry mixture across the road.
• It only takes about 2–4 hours to dry, so the work is usually finished in one day.

Chip seal

Chip seal takes a few days and involves multiple steps:

• Notifications are given 24 hours with date and explanation of tasks for residents and businesses prior to work being conducted.
• “No Parking” signs go up the day before.
• On the first day, Cartow will relocate any vehicles left on the street to an adjacent area. The road is swept clean and closed to traffic.
  • An oil truck sprays the road with oil.
  • A second truck spreads small gravel (“chips”) over the oil.
  • Rollers press the gravel into the road surface.
  • Afterward, sweepers clean up loose gravel.
  • The road is reopened while the treatment sets over the next one to two days. Please drive 15 mph during this time.

Then comes the fog seal:

• The road is closed again, and another thin coat of oil is added. This helps the chip seal last longer and gives the road a clean, black finish.
• Once dry, the road reopens to traffic.

Final steps

After the treatment, new road markings are painted. Most are replaced as they were, but sometimes the Transportation Division updates the striping to improve safety or traffic flow.

Before any surface treatment, crews fix cracks and replace damaged spots on roads that are otherwise in fair condition. This prep work usually happens in the fall or spring before summer treatments begin.

What are my responsibilities during a surface treatment?

• Do not park on the street from 7 a.m. to 3 p.m. until the “No Parking” signs are removed.

• Do not allow sprinklers to water the street the day of the surface treatment.

• Stay out of the construction zone.

• If applicable, follow temporary speed limit signs.

My vehicle was towed off of my street. How can I find it?

If a vehicle is still parked on the street the morning a surface treatment is scheduled, it will be towed to a nearby street so the work can happen. We record the vehicle’s location and give the information to the police so it isn’t reported as stolen. To find out where your vehicle was moved, call us at 801-535-2345.

Will this interfere with my weekly trash pick up?

The Streets Division schedules the timing of the surface treatment with the Waste and Recycling Division. This project will not interfere with weekly waste and recycling service.

How long will my street be closed?

How long a street is closed depends on things like the type of surface treatment, weather, and how complex the road is.

For slurry seal, which is a quicker, one-day process, the road usually closes at 7 a.m. and reopens in the early afternoon. Please don’t walk or drive on the fresh surface until it’s officially reopened—this helps prevent damage to your vehicle, your property, and the new road.

Chip seal takes place over several days, but the road will only be fully closed twice: once for the chip seal and once for the fog seal. Each closure starts at 7 a.m. and ends in the early afternoon. Between those two phases, the road stays open, but it may have loose gravel. During this time, please drive slowly—15 MPH or less—to stay safe and protect your vehicle.

Will I have access to my driveway during the surface treatment?

Streets will work to minimize disruption to residents and businesses and you will be notified in advance if access will be restricted. If you have special needs, please call us at 801-535-2345.

Will you be reconstructing the street?

No, a surface treatment is not the same as a full road reconstruction. Surface treatments are used to extend the life of the existing road. This helps delay the need for a full rebuild.

A full reconstruction is much more expensive and takes a lot more time. It involves removing and replacing all the asphalt—and sometimes even the road base, curbs, gutters, and sidewalks. Surface treatments are quicker, more affordable, and less disruptive for drivers.

If my street is receiving a surface treatment this year, does that mean it’s going to be reconstructed soon?

Probably not. If your street is in good enough shape to receive a surface treatment, then it’s likely that it isn’t near the top of the list for a full reconstruction.

My street looks to be in really poor condition. Will it be resurfaced soon?

Probably not. If a street is in really bad shape, it will eventually need a full reconstruction. Putting a surface treatment on a street with severely damaged asphalt doesn’t help much and won’t extend its life. It would also waste public money since the surface treatment would be removed when the road is rebuilt anyway.

Why are surface treatments rescheduled?

Surface treatments are usually rescheduled for one of two reasons: bad weather or equipment problems. These treatments need warm, dry weather to work properly, but sometimes a summer storm can delay the work. Other times, our equipment may break down. If either of these happens, we’ll leave a notice on your door and let you know when the work will be rescheduled.

Why does the city use three different types of surface treatments?

Overlay, slurry seal and chip seal are used for different types of roads based on their condition and usage factors. If the road is in really bad shape, the City is sometimes able to do overlay rather than a road reconstruction. The City uses a chip seal if it’s in poor to decent shape. For roads that are in fair or good condition, a slurry seal is a better choice.

My road was reconstructed last year. Why is the city already working on it again?

The best time to apply a surface treatment is one to two years after a road is built. This helps seal the road and keep water out, which can damage the asphalt over time. Doing this early on gives the road the best chance to last longer.

How does the city determine what roads receive a surface treatment?

Salt Lake City picks streets for surface treatment based on several factors, including their condition (called the Overall Condition Index), the type of road (major, minor, or neighborhood), how cost-effective the treatment is, and whether the road is a good fit for it.

Increased pavement maintenance is one of the projects funded through Funding Our Future sales tax.