Trains operate using the Bombardier-built 5000-series railcars; each train consists of two cars. Average weekday boardings of 7,063 were reported in September 2012. Until late 2009, the Yellow Line was operated with the 3200-series cars that were specially equipped with roof boards that, until late 2004, held pantographs (the roof boards remain on cars 3441-3456 to this day even after they were officially reassigned to the Brown Line). Occasionally, the Yellow Line borrows cars from the Red Line when short on cars.