The aim of the study is to provide recommendations on the parameters of metro (subway) systems, such as the length of the system and the number of stations, in the capitals of the Baltic States Vilnius, Riga and Tallinn, if metro systems are installed in these cities in the future. The article analyzes the regularities of the parameters of the metro systems in the cities of Europe, America and the Baltic Sea region, in order to determine the relationships between the length of the metro, the number of stations and such city indicators as area and population. Based on empirical data and relative indicators, it was found that the development of the metro system is strongly correlated with urban density and social factors. The study revealed that European cities are characterized by higher infrastructure density even with a lower population, while American cities more often form long but less frequently located lines. Meanwhile, the cities of the Baltic region remain infrastructural lagging behind both in terms of territorial and demographic coverage. The results of the study allow to formulate strategic recommendations for the Baltic cities – the development of the metro must be oriented towards social accessibility, territorial efficiency and sustainable urban growth.