An observation car/carriage/coach (in US English, often abbreviated to simply observation or obs) is a type of railroad passenger car, generally operated in a passenger train as the rearmost carriage, with windows or a platform on the rear of the car for passengers' viewing pleasure. The cars were nearly universally removed from service on American railroads beginning in the 1950s as a cost-cutting measure in order to eliminate the need to "turn" the trains when operating out of stub-end terminals.
The push-pull mode of operation removes this limitation. In Europe, various trains are now fitted with observation cars at either or both ends.