Sustainable freight transportation is aimed at reducing environmental emissions and social inequity along with economic inefficiency to drive the business. Lack of a continuous sustainability assessment and monitoring tool increases the reluctance of freight transporters to adopt world-class sustainability practices. This paper attempts to develop the performance index for a sustainable freight transportation system by innovatively integrating the Consensus Model (CM) with the Fuzzy Evidential Reasoning Algorithm (FERA). A CM has been used to determine the degree of importance of each Key Performance Indicators identified across three dimensions of sustainability. FERA has been used to aggregate subjective judgments with crisp quantitative values. This approach has a unique capability to handle various uncertainties related to impreciseness in decision-making. This study has demonstrated the use of an integrated approach for developing a performance index of the freight transportation system. Sensitivity Analysis of the model provides logical inferences and an understanding of the robustness of the model outputs. It can be interpreted from the results of the study that the firms with higher profitability in the market are focusing more on making their operations sustainable. A proportionate approach of firms towards the economic, environment, and societal well-being, may assist in achieving higher sustainability. © 2021, Springer Science+Business Media, LLC, part of Springer Nature.