This paper examines the decision-making process surrounding the development of new urban public transport systems in the UK, Drawing on the results of a worldwide survey of new (post 1974) and planned urban public transport systems, a number of objectives and factors have been identified which are central to the decision-making process, The objectives are criteria which must be satisfied in order for the system to be implemented and include obtaining the funding, keeping the costs down and maximizing the patronage, The factors influence whether or not the objectives can be met and can be divided into five groups relating to political, financial, planning, design and physical issues, The relationships between the factors and the objectives are examined, and a number of guidelines are proposed to assist in the planning of urban public transport systems, including the need for a political consensus, the use of appropriate existing rail alignments, and the contribution of traffic restraint schemes, in obtaining authorization and funding for systems.