Accurate, consistent, and repeatable distress evaluation surveys can be performed by using the Distress Identification Manual for the Long-Term Pavement Performance Program.  Color photographs and drawings illustrate the distresses found in three basic pavement types, asphalt concrete-surfaced, jointed (plain and reinforced) portland cement concrete, and continuously reinforced concrete.  Drawings of the distress types provide a reference to assess their severity.  Methods for measuring the size of distresses and for assigning severity levels are given.  The manual also describes how to conduct the distress survey and measure cracks in the pavement.  

A copy of this publication can be found through the Federal Highway Administration website as well as here.