Application of Factor Analysis in Maintenance Management of Low Volume Roads

Abstract

The maintenance management of low volume rural roads in developing countries presents a variety of challenges to road designers and managers. Rural roads comprise over 85% of the road network in India, and their serviceable condition is crucial to the rural economy. The present study aims to develop an index for rating the condition of pavements of low volume rural roads under the national rural road program, namely Pradhan Mantri Gram Sadak Yojana (PMGSY) in a typical district in India, so that the index can be used as a decision support tool for the maintenance management of low volume rural roads. A visual condition survey of the selected roads included evaluation of the conditions for shoulders, drains, cross drainage structures, camber and pavement distresses viz., potholes, crack areas, and edge breaks at every 200 m section. The data were collected for a period of three years. A multivariate technique, factor analysis, was used to calculate the index number for every 200 m pavement section in the study area. Data on 12 indicators of pavement conditions were factor analyzed (principal components and varimax rotation) and four factors were extracted, namely distress factor, side drainage factor, shoulder vegetation factor, and cross drainage factor. A total variance of 77.8% was explained by these factors. The index numbers were standardized as percentages for easy comparison across all sections and named as Visual Condition Index (VCI).