This thesis is a study of political decision-making processes related to transport matters. It explores the factors underlying these decisions and their social impact. The thesis is divided into three parts. Part One constitutes a theoretical discussion of themes related to the study of urban transport policies: the urban phenomenon, the state, and transport planning. In Part Two, the history of transport policies in London is related. The period between 1965 and 1980 is studied in detail while the decades before 1965 are briefly examined to provide a background. Finally in Part Three, the history of the period under consideration is discussed in the light of the theoretical developments of Part One. One of the main points raised by this discussion is that elected members respond to pressures from non-state organisations which are likely to yield electoral and economic impacts. It also appeared that the discrepancy between large scale plans and modest implementations which characterises the period under study was the result of the behaviour of members of organisational group, i.e. planners and elected members, working within the state and each pursuing their own interests. The major point raised in the thesis is that low income groups in London suffered disproportionally from negative consequences of transport policies and trends. This was accounted for by the fact that these groups have less political strength than other groups and that their limited means do not allow them to escape deteriorating modes of transport by using other ones.