The Evaluation of the Expert System for Pavement Evaluation and Rehabilitation (EXPEAR) in Washington State

The EXPEAR system for Pavement Evaluation And Rehabilitation (EXPEAR) is an advisory system to assist the practicing engineer in evaluating a specific pavement section and selecting pavement rehabilitation alternatives. The objectives of this study were both to evaluate EXPEAR by using Washington state project data to determine the reasonableness of the program's output in comparison to WSDOT's current procedures, and to identify any existing program "bugs: and/or desirable program enhancements.

To evaluate EXPEAR program output, pavement design and condition data were entered from four test sections in Washington. After the pavement data were input, the EXPEAR output results were reviewed subjectively for reasonableness and compared to the state's current procedures for determining appropriate rehabilitation.

Although EXPEAR offers several positive attributes, this study found problems with its output. For example, the transverse cracking model predicted cracking that was more severe that WSDOT has observed. Often EXPEAR predicted distress trends that were not reasonable. Also, a test of the risk of the different rehabilitation options appeared to be missing from the program.

The researchers concluded that the high level of effort expended in creating EXPEAR is commendable and that a system of this type can be a useful tool not only for pavement design but also as a scoping and planning tool for pavement rehabilitation. However, WSDOT will probably not use EXPEAR in its present form because the performance predictions of both existing pavements and rehabilitation strategies were generally inconsistent with what has been observed in Washington
Publication Date: 
Sunday, April 16, 1989
Publication Number: 
WA-RD 169.1
Last modified: 
10/12/2016 - 15:41
Holly A. Simmons, Linda M. Pierce, Joe P. Mahoney, Newton C. Jackson.
Washington State Transportation Center (TRAC)
Number of Pages: 
Computer programs, Cracking of concrete pavements, Expert systems, Evaluation, Mathematical prediction, Pavement design, Pavement distress, Pavement performance, Performance, Portland cement concrete, Rehabilitation (Maintenance)