Valuation of low volume roads in Spain. Part 2: Methodology validation

A methodology for assessing the condition of rural roads using the Road Condition Index (RCI) was developed by the authors in Part 1. However, such a theoretical methodology must be validated in order to corroborate its practical suitability. Therefore, a total of 41 rural roads (total length 109 km) were studied throughout 20 of the 50 Spanish provinces. Climate, the characteristics of the road surface and the use of the adjoining land were considered when selecting the study sample. Principal Components Analysis (PCA) was used to examine the Condition Index (CI) values for the roads analyzed. The information accounted for by the first three factors was then examined by Hierarchical Ascendant Classification (HAC) to place the roads in groups with similar characteristics. Thus, the influence of the different Condition Indices (CIs) on overall evaluation status could be established and the possible similarities between roads could be studied as well. The results allowed the current condition of the roads to be described and helped to identify those features with the greatest influence on this status.