Basic asphalt roadways are compressed during the initial road laying process. The compression from the rollers creates minute sub-surface cracks that enable water to enter below the asphalt surface. Water seepage during freezing winter conditions causes roadway expansion and breaks the bond of the asphalt. Freezing water loosens the roadway surface, creating potholes. Chip sealing seals any exposed roadway cracks, preventing water from seeping into the asphalt and creating potholes during the winter.
Asphalt roads have a limited lifespan. Exposure to hot and freezing conditions, road use and sun damage from ultraviolet penetration degrade the surface over time. Durability of roads is directly impacted by the amount of damage to the roadway following the initial lay of asphalt. Asphalt roads exposed to winter conditions for a few years degrade far faster than asphalt roads with chip sealing applied.
Winter conditions accelerate the damage to existing roadways. Basic asphalt roads without chip seals are more likely to develop potholes and expansion cracks than chip sealed roadways.
Roadway closures are minimized during winter months with chip seal repairs. Replacement of asphalt pavement requires the removal of the old asphalt, resurfacing the underlying layers and application of the new roadway. During winter months, the amount of time available to repair a road may be limited by weather. Because chip sealing can be applied over crack seals and potholes, the roadway may be closed for only a short amount of time to make initial repairs and lay the chip seal.
Recently chip sealed surfaces have more rock aggregate on the surface of the asphalt, providing better traction than older paved asphalt roadways. Conversely, loose gravel from the chip sealing process may damage vehicles when tires throw the rocks.