A fuzzy multicriteria method for ranking the factors that influence the settlement of Brazilian highway speed limits

The process of settling highways speed limits involves a high number of factors, not clearly defined in terms of an order of relevance that allows the expert – responsible for making the decision – choose the best solution. Since the establishment of a speed limit is based on subjectivity, being governed by uncertainty and imprecision, the fuzzy logic stands out as an alternative for the solution of the problem. Therefore, experts from the area were questioned about the influence of pre-determined factors on highway speed limits and, after that, a multicriteria fuzzy decision-making method, optimized by a genetic algorithm, was used, so that the variables could be ordered concerning weights and, consequently, relevance. The method converged to satisfactory results, which may allow not only the conception of an expert system for the settlement of speed limits, but also the application in other fields.