The paper presents the methodology of evaluating diversified mass transit systems (MTS-s), operating in different European cities. The evaluation of MTS-s is formulated as a multiple criteria ranking problem and the methodology of Multiple Criteria Decision Making/Aiding (MCDM/A) is applied to solve it. The authors carry out and present all phases of the solution procedure of the multiple criteria decision problem (DP). Thus, they define the variants and the consistent family of criteria. They model the decision makers’(DMs’) preferences, including their sensitivity and perception of the importance of criteria. They review and analyze a spectrum of MCDM/A ranking methods, including: Electre III, Oreste, AHP, UTA, and finally select the most appropriate ones that fit best the specific character of the public transportation systems’ evaluation process. They run computational experiments resulting in the generation of the final rankings of the MTS-s.