TRANSPORT REVIEWS, 1992, VOL. 12, No. 1, 15-32 Innovations in urban transport and the influence on urban form. An historical review By G. A. GIANNOPOULOS Transport Section, Aristotle's University of Technology, 540 06 Thessaloniki, Greece and G. CURDES Institute for Town and Country Planning, Aachen University of Technology, 51 Aachen, Germany This paper draws on work of the international collaborative programme URBINNO on innovation and urban development. It is based on analysis of data from eight urban areas in Europe. After presenting the theoretical aspects of the interrelation between transport innovation and other factors characterizing an urban area, the paper examines the evidence in practice. In the case studies all transport innovations du ring the last 100 years were related to corresponding changes in the urban form. Certain conc1usions are drawn. It appears that, although interrelation between transport innovation and urban form does exist, towns and cities are socio-physical systems with a high stability and resistance against 'short- term' transformation. In general, transport innovations have short life cyc1es in relation to the permanence of an urban morphology. Therefore, it can be said that transport innovation and urban development build the synthesis between new needs and technologies in a form which is comparable to the specific (and different) urban scales .. Transport innovations have left significant marks on the form of towns. None formed a town in total. There is always a mixt ure of influences from different fields. However, from the towns in different stages of development that were examined, it can be seen that the influence of innovations on urban form is high in an early stage of development and lower in a dense and built up town. 1. Introduction This paper is derived from research under an international project called 'URBINNO-Innovation and urban development: the role of social and technological change'. The authors are members of working group 4 (built form, environment and land use). The purpose of the URBINNO project was to analyse the influences of ideas and innovations in the process of urbanization during the last 100-150 years. The aim of group 4 of the URBINNO project was to use the geographical and morphological pattern of the urbanization process as a basis for research, in addition to the usual research by data. The physical elements of urban space have the same quality as statistical data, in that these elements are on the one hand a product of the past and on the other are conditions for present and future life. Only some elements and relations in the physical structure can be altered within any generation, which does not make for rapid change in infrastructure. Additionally, the overall form of an urban area is defined du ring its early growth phase, and remains very stable over time, and the discussion of the effects of transport innovation on urban form should take cognisance of this inherent stability. The following are definitions ofinnovation given by Schubert (1988): 'new ideas set in motion to solve urgent problems'; 'new alternatives not weH known'; or 'new 0144-1647/92 $3000 © 1992 Taylor & Francis LId.