•Prioritization of transmission line projects in the prospection stage is studied.•Two-stage multicriteria georeferenced express analysis is proposed.•Generalization of Dijkstra’s algorithm is proposed for multicriteria path planning.•General scheme of multiobjective decision making under uncertainty is applied.•Techniques of preference modeling in a fuzzy environment are applied. The objective of the present research is to develop methodological and computing tools to support the analysis and prioritization of new electric transmission line projects, in the prospection stage, aimed at greater efficiency and effectiveness of the advanced preparation of concessionaires and investors for participating in the auctions. These auctions are organized by the granting authorities (usually, regulatory agencies). The process of elaborating decisions on auction lots (possible “candidates”) is divided into two stages. The first one is associated with a study on relevant criteria modeled on the basis of applying Geographic Information Systems. The purpose of the first stage is to form the most rational multiobjective estimates of new transmission lines, which can be constructed and operated on analyzed lots. The included criteria are defined with a high level of uncertainty. Considering this, the general scheme of multiobjective decision making in conditions of uncertainty is applied to construct robust multiobjective estimates. This scheme presumes the building and analysis of payoff matrices. The solution of multiobjective problems for representative combinations of initial data, states of nature or scenarios is based on the use of a generalization of the well-known Dijkstra's algorithm (related to graph optimization, permitting the construction of transmission line routes) to analyze multiobjective problems. The second stage is directed at the definition, from the set of lots analyzed at the first stage, of a portfolio of the most appropriate and favorable areas for implanting transmission lines. This stage is based on applying techniques for preference modeling in a fuzzy environment within the framework of models of multiattribute decision making. Their use permits one to adequately consider criteria of quantitative character as well as criteria of qualitative character, whose estimates are based on knowledge, experience, and intuition of involved experts. The paper results are illustrated by a case study which demonstrates the rationality of their practical application, in addition to the strategic role that these results can play for concessionaires and investors, participating in auctions due to their ability to meet a wide range of criteria.