Analytical Review of Modern Methods for Assessing the Condition of the Railway Track

Maintaining a railroad track in good condition requires constant monitoring of its parameters. One of the main indicators is the track position in space and time. This position is characterized by such indicators as longitudinal and transverse profile, track position in plan, track distortions, track width. These parameters directly affect the dynamics of interaction between rolling stock and railway track. The difference between the actual and design positions for each parameter can lead to speed restrictions and, in some cases, to the complete closure of traffic on the section. In addition, the analysis of these parameters makes it possible to identify critical conditions at an early stage and plan preventive maintenance. However, for a comprehensive assessment of the condition of a railroad track, it is advisable to consider not one single parameter, but their combination. In recent years, numerous studies have been conducted in different countries to find the most objective Track Quality Index (TQI). Track quality indices are abstract values that combine and calculate data obtained from track measuring instruments according to a certain algorithm. The result of the calculations is a certain numerical value that characterizes the condition of a particular section of track. This makes it possible to compare different sections with each other, find the highest priority areas for repair, and plan track maintenance work. The analysis of the database of consistent measurements of one section and the operating conditions on it makes it possible to calculate the rate of degradation of the geometric parameters of the track. This, in turn, creates prerequisites for predicting the occurrence of faults. This paper aims to consider different approaches to assessing the geometric parameters of a railway track using track quality indices.