The paper presents the unified transport investment assessment methodology developed for Latvian transport policy planning, that consists of mapping which allow comprehensively review transport infrastructure and links to the national energy and climate plans as well as connectivity of regional and local communities. The study consists of seven tasks: (1) Analysis of transport infrastructure and its influencing indicators; (2) System analysis of transport planning data; (3) Mapping of transport infrastructure and policy interventions; (4) Initial evaluation of transport policy interventions; (5) Methodology of economic evaluation of planned investments; (6) Evaluation of policy interventions scenarios; (7) Recommendations for future development of comprehensive transport planning. The methodology was provided on the base of comparative advantage analysis – Analytic network process that allows assessment of transport investments in cases with many missing and incoherent data and IT assets deficiency.