Resemblance.
Chicago Transit Authority (CTA) 2400-Series car 2455 (Boeing-Vertol, 1976-1978) is seen leading a "Loop Tour Train" around the outer track of the Union Loop in Chicago, passing a revenue service Orange Line train of 2600-Series cars (Budd, 1981-1987). Rapid transit cars purchased by the CTA have been of a very similar design since the 2200-Series, and the resemblance between these two models is noticeable here.
