Advisory System for Design of Highway Safety Structures

A prototype knowledge‐based expert system for assisting engineers in selecting, locating, and designing construction and retrofit projects for traffic barriers, such as roadside barriers, median barriers, bridge rails, and crash cushions is described. The system uses design principles of traffic barriers, information provided through interviews with experts, and information on a particular site to generate feasible candidate designs. These designs are processed by an evaluation system that includes finite‐element analysis, a weighting mechanism, and a cost‐benefit model. Color graphics and an exaplanation module illustrate the design. An integrated rule‐ and frame‐based expert‐system shell facilitates implementation of the knowledge‐based system on a microcomputer with the help of external routine links, data‐base access, and a graphical interface. Visual knowledge, which is preserved through scanned images, is replete with educational benefits to highway engineers. An example bridge‐rail‐retrofit procedure demonstrates the approach to development of the knowledge‐based system.