Development of track condition assessment model based on visual inspection

Inspection and evaluation of railway track conditions are usually accomplished by analysis of geometric data obtained from track recording cars. Although most geometric deviations can be recorded by these cars, track structural defects cannot be identified during automated inspections and the causes of track problems cannot be fully recognised. This limitation makes the efficiency of current maintenance approaches questionable. This research proposes a new method of track evaluation based on the observation of track structural defects. Dominant observable structural distresses were studied and a methodology was proposed to translate structural problems into a meaningful numerical rating. The contribution of a track structural defect to track quality was investigated and a track structural quality index model was developed. This index is a function of the severity and density of distress types. To examine the practicability and applicability of the new index, a practical use of the model is presented.