The Blue Line extension project of the Montreal metro will redefine mobility in the eastern part of the city by strengthening connectivity and the appeal of public transit. Estimated at nearly $7 billion, this large-scale project includes the addition of five new stations and the excavation of a 6-kilometre tunnel, connecting Saint-Michel station to the Anjou borough. Its realization involves numerous challenges, including technical complexity, urban integration, market conditions, political sensitivity, and multiparty governance.