Road condition rating based on factor analysis of road condition measurements

Summarising indices of road condition are used in road maintenance management for aggregating the vast amount of data and for communication purposes. In this paper, a road condition rating based on factor analysis of measured road condition variables is developed to calculate values for an existing or a new condition index. Three factors were extracted from road surface profile and deflection measurements: structural factor, roughness factor and transversal unevenness factor. Factor scores are calculated as the mean of the standardised values of log-transformed variables in each factor. Condition rating, calculated as the weighted sum of the factor scores, is used for maintenance policy evaluation.