Functional evaluation by visual condition survey

The visual condition survey, also known as distress survey, is the first step to functional evaluation of the pavement and perhaps the most useful of all types of surveys. In some cases, it is a stand-alone procedure for decision making. 

The visual condition survey of pavements consists of (a) recording of pavement distresses, (b) pavement rating and (c) detailed presentation of pavement condition. 

The visual recording of pavement distresses is usually conducted by crews of at least two trained people. The collection of pavement distress information may be carried out by viewing the pavement surface from a slow-moving vehicle or by walking on the pavement 

Visual condition surveys require the use of GPS facility and the use of survey forms and distress identification manual. Table 16.1 provides some details on the type of distresses to be recorded during a visual condition survey of flexible pavements carried out by the Highway Engineering Laboratory of the Aristotle University of Thessaloniki (AUTh). 

In case of descriptive rating of the pavement condition, the terms good, fair and bad are usually used. The meaning of the above terms could be as follows  

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