In this paper, we argue that a large-scale demand responsive system is the missing element from the spectrum of the urban transport modes. To this end, we provide a comprehensive analysis addressing this broad question from several aspects including the customers' perception, various technical aspects, and the related societal aspects. In each case, we are able to give sound arguments why a mass demand responsive transport (DRT) service can improve the current situation considerably. The mass DRT will not make other transport modes obsolete, but can complement them in surprisingly efficient manner leading to considerable internal and external cost savings — a true win-win situation the modern computer and information technology has enabled.