The article explains how Multiple Criteria Decision Making/Aiding (MCDM/A) can help solve complex transportation problems with multiple objectives. It provides a universal set of rules and methods to support decision makers in analyzing and solving these issues. The process of MCDM/A is described, along with the key players involved. The article also discusses different methods used in MCDM/A, such as ELECTRE III/IV and AHP, and presents a real-world case study on selecting low-floor trams for a fleet. This information is aimed at researchers, students, professionals, politicians, and managers dealing with transportation decisions.