GO Transit's rolling stock uses push-pull equipment. Its passenger car fleet is composed entirely of Bombardier BiLevel Coaches built in Thunder Bay, Ontario. These double-decker coaches, easily identifiable by their elongated-octagon shape, were designed in the mid-1970s for GO Transit by Hawker Siddeley Canada as a more efficient replacement for GO's original single-deck coaches, built by the same company. Later coaches were manufactured by Can-Car/UTDC and the most recent coaches are produced by Bombardier Transportation, who now owns the designs and manufacturing facilities. GO Transit owns approximately 700 BiLevel Coaches, which are also used by a number of other commuter railways across North America. They have a seating capacity of 162 people per coach, or 1,944 per train. All upper levels of the coaches on rush hour trains are designated "Quiet Zones".