<p>Building Information Modeling (BIM) fills the gaps of traditional methods, reducing design errors in road infrastructure projects. Its application aims to strengthen collaboration and facilitate the exchange of data between different stakeholders, which is a major asset in the management and optimization of road projects. During the preliminary design phase, choosing the best alternative is a crucial step, as it directly influences the quality and sustainability of the final infrastructure. The literature review revealed that existing methods were mainly based on the use of two-dimensional cartographic documents, thus limiting the visualization and analysis of the different possible options. This article proposes an innovative approach highlighting the use of INFRAWORKS, a 3D tool for projecting different alternatives in a realistic environment. The main objective of this research is to determine the optimal road alignment according to carefully selected criteria, for the renewal of a road section vulnerable to flooding, connecting the city of Sidi Belattar to the RN 90, located on the left bank of the Chellif, in Algeria. In order to structure and solve the problem of selecting alternatives, the analysis of multi-criteria decision support methods (MCDM) was adopted, combining two complementary methods: TOPSIS (Technique for Order of Preference by Similarity to Ideal Solution), used to rank the alternatives, and ELECTRE III (Elimination and Choice Translating Reality), allowing prioritize them according to their relevance. The results of the ranking of the alternatives were consistent, recommending the Second Alternative as the optimal solution to replace the vulnerable section of the existing alignment. Ultimately, this approach constitutes a significant advance by integrating BIM and MCDA, thus illustrating an innovative approach to improve the planning and design of road infrastructures from their early stages of development.</p>