Montreal's Metro trains are made of low-alloy high-tensile steel, painted blue with a thick white stripe running lengthwise. Trains are assembled in three-, six- or nine-car lengths. Each three-car segment element consists of two motor cab cars encompassing a trailer car (M-T-M). Each car is wide and has three (MPM-10) or four (MR-63, MR-73) wide bi-parting leaf doors on each side for rapid passenger entry and egress. Design specifications called for station dwell times of typically 8 to 15 seconds. In response to overcrowding on the Orange Line, a redesign of the MR-73 cars removed some seats to provide more standing room. The newest Bombardier MPM-10 trains are open-gangway, allowing passengers to move between cars once on board such that the passenger load is more evenly distributed.