Double Deck Motor Bus in Chicago

The double-deck motorbus was primarily designed to appeal to sightseers, but also as an alternative to the streetcar.  This card is from about 1917, when this was the only double-deck bus service in Chicago. A few years later there were more routes and numerous competitors. Although the height of the bus was the source of its appeal, it was also the cause of its demise, because the buses were too tall to travel under rail viaducts.