Cracking is one of the main distresses and concerns considered in the pavement design process. It is the primary mode of deterioration in asphalt cement pavements. Cracking occurs in a variety of forms: transverse, thermal, longitudinal, block, and alligator shapes. Cracks need to be treated promptly because they create openings for moisture & dust to penetrate into the pavement layers. Neglecting cracking usu­ally leads to accelerated deterioration of the pavement, resulting in significant problems such as potholes or base failures, which cause the serviceability of the pavement to decline. The cracks should be treated first before new overlay.

Below is an example on how fast the crack can develop and reflect from an old surface into a new one: