It is resistant to the abrasion of moving wheel loads and transfers the wheel load to the underlying layers.

It provides a skid-resistant surface.

It may provide light-reflecting qualities.

It may provide a different texture or color to distinguish areas, such as shoulders and travel lanes.

Crushed gravel – natural gravel that has been crushed to change the particle shape from round to angular and the surface from smooth to rough.

Crushed stone – large stone or pieces of bedrock that have gone through a series of crushing processes. In Texas, this stone is predominantly limestone, but also includes sandstone.

Natural limestone rock asphalt – limestone rock asphalt is a limestone that is naturally impregnated with asphalt.

Lightweight aggregate – expanded shale, clay, or slate produced by a rotary kiln method. Due to its low specific gravity (or light weight) it tends to cause less windshield and vehicle damage. It also has excellent skid-resistant properties.

Crushed slag – produced as a by-product of steel production. When crushed and used as a seal coat aggregate, it can give good wear and skid resistance.