Fatigue cracks will occur over time due to bending of the asphalt or pavement. Pavement lacks flexibility and will crack. The weight of vehicular traffic will cause bending and eventually lead to cracks. The more traffic the sooner cracking will appear and the more severe the cracks.
Water underneath the pavement and in between small cracks and crevices in the pavement will expand when freezing in the winter. The expansion of the ice in between the pavement will enlarge existing cracks and form new cracks.
The sun depletes the binding cement in the dried asphalt, causing the gravel inside the pavement to loosen and crumble. Over time, the sun can weaken the integrity of the pavement, making it easier for cracks to form.
The quality of the material underneath and the thickness of the pavement can increase the likelihood of cracks developing. Thin pavement is more likely to bend under the stress of traffic and will be more likely to crack as a result. Soft, sandy ground underneath the pavement will lack the support needed by the pavement to prevent bending under stress. This will also lead to cracking.