The key scientific contribution of the research described in this dissertation is the development of an optimisation framework that incorporates pedestrians in urban traffic management systems. The research is based on the principle that the overall travel cost should be minimised for all the users of the traffic network including pedestrians and vehicle occupants. This framework is an improvement on existing traffic management systems which have traditionally been designed to result in minimum travel time for vehicular traffic limiting pedestrian considerations to safety issues only. Overlooking pedestrian travel costs can result in a design that is suboptimal for society, especially if pedestrians comprise a considerable proportion of all the network users. Traffic management systems focussed only on vehicle flows can also inhibit efforts to promote walking. The dissertation examines in detail the evolution of pedestrian policies in Britain in an attempt to determine the underlying principles behind the pedestrian control measures that exist today. Various pedestrian street crossing policies are then studied in detail using micro-simulation methods to analyse the effects of these polices on pedestrian and vehicular traffic. The micro-simulation model employed is VISSIM which is used for its more flexible pedestrian modelling capabilities. The base data on various traffic parameters, for this work, was collected at Marylebone Road in London. A cost analysis is performed based on relative values of time for various signalisation policies and for different levels of vehicle and pedestrian flows. In addition, an analysis of pedestrian exposure to vehicle emissions is undertaken that employees an integrated use of micro-simulation, modal emissions and air quality models to study the effects of approaches used to improve traffic flow of pedestrians. The results are discussed for their policy implications for the design of signalised networks in areas of high pedestrian activity and how changes can lead to more optimal outcomes.

This practice-based study explored the relationship between text-based messages and audio-based communication within the contemporary urban environment. Issues relating to signage overload and urban movement were identified at an early stage in this study, and pedestrian wayfinding was then selected as a form of communication that allowed for exploration of all the key issues. Two practice-based approaches to the research were developed that utilised both analysis and experimentation. Initially informal and then subsequently structured investigations of text and audio-based communications in real environments were conducted. Subsequently structured case studies were undertaken in carefully selected external environments, whence a series of charts and macroscopic drawings were produced facilitating data collection and analysis by the researcher. Analysis of findings indicated that whereas in interior public spaces the combination of text and audio in messages was relatively well established, there were few examples of wayfinding design that employ a combination of text and audio design currently existing within the external environments investigated in the case studies. It was also indicated that signage overload and visual clutter made pedestrian wayfinding problematic in the urban environment. Speculative design proposals investigate possible solutions to these issues. From this practical and theoretical basis guidelines have been derived with a view to supporting practitioners in this new area.

Le réseau routier est un outil technique ancré dans son territoire. Sa conception, sa construction et son entretien sonttraditionnellement vus comme étant le reflet des conditions géographiques et économiques du milieu. Ce doctoratanalyse l’impact du contexte réglementaire et administratif du réseau sur les choix techniques effectués.La comparaison de l’évolution des réseaux de transport urbains au XXème siècle dans les régions londonienne etparisienne montre en effet des divergences importantes. Cependant, une forte continuité historique existe, aussi bien enFrance qu’au Royaume-Uni, dans la sélection des solutions techniques adoptées. Ce travail de doctorat identifie le faitque cette stabilité est le reflet de la stabilité du cadre légal. L’analyse historique effectuée exclue clairement l’approcheinstitutionnaliste du comportement des administrations et entreprises en charge du réseau. En effet, au cours de cettelongue période, ces dernières ont beaucoup changé, les personnels aussi, mais les réactions des agents demeurent trèssimilaires.Depuis les années 1990, les administrations et institutions en charge du réseau ont été profondément réformées. Cesréformes ont été menées sur fond de crise financière, de baisse dramatique du retour sur investissement desinfrastructures routières et de la chute partielle de compétitivité du mode de transport automobile.Ces réformes conservent des spécificités nationales fortes mais la seule explication trouvée à leur cohérence globale estle fait que le réseau routier ne peut plus être considéré comme une défaillance du marché. Les outils de collecte depaiement à l’usage existent, sont de plus en plus couramment utilisés, et il serait logique de voir l’infrastructure routièreentrer rapidement dans le cadre des autres industries de réseau. / A road network is an infrastructure rooted in its territory. Its design, construction and maintenance are traditionally seenas mostly conditioned by the local physical environment and its economic conditions. This doctorate however analysesthe impact of the regulatory and administrative environment on design choices.An included historical comparison between London and Paris XX century urban networks highlights very different trendsin design choices. However, consistent decision making patterns have developed independently over time in the Britishand French networks. This doctorate demonstrates that these decision making biases are dictated by the legal frameworkof each country, which constrains government’s ability to take part in the road network development process. Becauseadministrative structures have significantly changed over time, they cannot explain the observed consistency.Since the 1990’s, urban transport network administrations and institutions have been profoundly reformed. These reformshave been made in the context of financial crises, reduction in infrastructure economic return and partial loss ofcompetitiveness of the automobile as a mode of transport.These reforms are different from country to country, but the only identified reason that would explain this trend is the factthat the road infrastructure is no longer a market failure. Pay-per-Use technologies of the road infrastructure are alreadyavailable, and represent a profound change in market structures. Some governments and national administrations arefinding themselves increasingly confined to regulatory duties and it is only logical to expect the road infrastructure totransform itself into a typical utility, operated by private companies.