Car 6000, a double-decker streetcar.
Car 6000 was built by the Pittsburgh Railways Company in 1912 as a model for future double-decker cars. It seated 112 and could hold 210 passengers total. The double-decker cars were usually limited to operation on route 73 Highland. At one time Pittsburgh had the largest double-decker car ever built. However, double-decker cars were gradually phased out of service between 1924 and 1927.