This paper presents a multi-year transmission expansion planning (TEP) model which considers the transmission congestion and the impact of generation investment cost in the planning horizon. The Benders decomposition approach is utilized which decomposes TEP into a master problem and two subproblems representing security and optimal operation. The operation cost due to congestion (OCC) is considered in the proposed model given that the congestion level is a proper criterion for measuring the degree of competitiveness in an electricity market. The model evaluates sensitivity of the optimal TEP to congestion level, planning horizon, and financial constraints. Regulators can utilize the proposed results to provide long-term TEP to market players and to develop incentive mechanisms to trigger generation investments. The proposed approach is applied to a hypothetical system and Turkish power system.