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Overall Condition Index (OCI), Deduct Values, and Distresses <br />Pavement distresses are dependent on pavement type and are rated by severity and extent. A street <br />with an OCI of 100 represents a new or recently rehabilitated street. This OCI value is the basis used <br />to analyze the surface treatment needs. Distress data are collected using handheld computers <br />(IPAQ's) and then uploaded to the pavement management software. The extended method (WSEXT) <br />rates severities and all their extents; this information is then used to determine a deduct value. A <br />segment's OCI is calculated by subtracting the deduct values from 100. As the condition of a street's <br />surface begins to deteriorate the OCI decreases. Asphalt distresses typically observed are alligatoring, <br />longitudinal and transverse cracks, rutting, and raveling. Distresses in concrete streets typically <br />observed and rated include cracks per panel, raveling, joint spalling, faulting, and crack sealing. <br />Descriptions of some common distresses are shown below: <br />Alligator Cracking: When the asphalt begins to crack in all direction it is called alligator <br />cracking. <br />Longitudinal Cracking /Transverse Cracking: These are cracks that are vertical (longitudinal) <br />and horizontal (transverse) in length. These distresses usually divide the piece into different <br />sections and which are caused by repeated traffic loading. The low- severity cracks are not <br />considered serious to the overall function and safety of the road. Medium to high- severity <br />cracks are usually caused by heavy traffic loads and environmental factors and can become <br />very serious distresses. The picture below shows longitudinal cracking. <br />IN <br />