Chip Sealing: Preserving Alaskaʼs Roads

The Alaska DOT&PF uses Chip Sealing (Bituminous Surface Treatment) as a proactive way to keep our roads in good shape. It’s a protective layer that keeps our road base dry and durable for a fraction of the cost of a full repave.

Why We Do It

• Waterproofing: Keeps water from penetrating the road structure to prevent base damage.

• Repair: Fills and seals cracks and raveled (pitted) surfaces on old pavement.

• Preservation: Seals the surface to minimize the aging effects of UV rays and weather.

• Value: Costs only 15%-20% of a standard pavement overlay.

 

The Process

1. Spray: A specialized truck applies liquid asphalt (emulsion) to the road.

2. Chip: A spreader immediately covers the liquid with crushed gravel (chips).

3. Roll: Rubber-tired rollers press the gravel firmly into the asphalt.

4. Sweep: Once cured (24–48 hours), mechanical brooms remove any loose excess rock.

 

Motorist Safety &
Work Zone Awareness

Speed limits are reduced in active work zones and for a few days following a chip seal application to allow the new surface to fully settle. Respecting these posted signs and slowing down is a strict requirement designed to protect your vehicle, preserve the road, and keep the public and our crews safe:

• Windshields: Driving at the Work Zone Speed Limit prevents your tires from kicking up loose chips and damaging the other vehicles.

• Paint: Lower speeds stop liquid asphalt from splashing onto your car’s bodywork.

• Road Quality: High speeds can "rip" the new rocks out before they are fully set, ruining the treatment.

• Worker Safety: Traveling at the posted limit ensures the safety of the highway workers just feet away from passing vehicles. Fines are doubled in construction zones.