Montreal’s light-rail system, the Réseau express métropolitain (REM), has reached a key construction milestone with the first successful run on the future airport branch, which will eventually link downtown to the Montréal-Pierre Elliott Trudeau International Airport. Project officials say the test marks the start of a new phase of work on the airport segment. It allows teams to begin validating rail infrastructure and communications systems on that portion of the network. Tracks have been installed up to the entrance of the future YUL–Aéroport–Montréal-Trudeau station, while excavation and construction continue inside the tunnel to connect the REM to the airport terminal. Construction of the Marie-Curie station in Saint-Laurent at the Technoparc is also nearly complete. Once that work wraps up, crews are set to shift their focus on finishing the airport station, including interior systems and passenger infrastructure. Teams still need to install rail systems, platform screen doors and safety equipment before beginning months of dynamic testing. If the work and testing are successful, work is set to be completed in the spring of 2027, with the official opening shortly after. Once complete, the airport line will offer a direct REM connection to Montreal’s international airport, a long-promised link that transit planners say will improve access for both residents and travellers. The airport station is part of a larger 67-kilometre REM network, a fully automated light-rail system designed to connect downtown Montreal with the South Shore, North Shore, West Island and the airport.