A study was conducted to identify possible solutions for redesigning a subway cab in order to improve the posture of drivers working in a restricted space. The approach used included the participation of a working group comprised of operations, maintenance, and engineering managers as well as several drivers. After 6 meetings in which different simulation techniques were used, the working group proposed changes for increasing the available space inside the cab and three seat designs. The involvement of the actors from the three departments affected by the changes, as well as the operators, throughout the process, was a determining factor in the advancement and acceptance of the projects. The fact that 400 cars are currently in service and must be modified means that it will take several years to implement the modifications in the entire fleet.