TheQualityof the train journey quality of the train journeyJourney is a decisive factorFactors in the choice of rail transportRail transport as a suitable alternativeAlternative to other modes of public transport. Quantitative methods have been used to comprehensively assess the train travel process. New data on the quality of the process have been obtained by addressing the needs of the entities involved. There is a tendency for the quality of rail travel to be improved by the implementation of practical measures which have the greatest positive impact on the most important criteria. The calculated Comprehensive Quality IndexComprehensive quality index K, which indicates the actual quality of a train running on a given route, is compared with a defined required quality level. Six levels of quality are identified: excellent, very good, good, average, poor and very poor. The recommended marginal comprehensive quality indexComprehensive quality index values for these quality levels and the difference between them depend on the economic level of the country. Applying the well-known principle that higher quality requires higher transport costs, marginal K values are recommended for three (strong, medium, weak) economic levels for different countries. A numerical example of the practical application of the model shows that the methodology presented in the study can be used for the assessment of the quality of individual train routes. Plans for future research into the development of rail passenger transportPassengertransport in the Baltic States are discussed. This development is aimed at connecting the Baltic rail network with lines in other European countries.