This chapter considers policies for investing in city transport in Britain over the last 100 years, with particular reference to public transport. The principal phases of new urban transport investment, which display considerable overlap, are summarized in Figure 1.1. Period, mode and investor of principal phases of urban transport development https://s3-euw1-ap-pe-df-pch-content-public-u.s3.eu-west-1.amazonaws.com/9780429401343/5920bac8-d29c-459e-8be9-5c603d3be404/content/fig1_1.tif"/> 71However, the summary requires qualification in several respects. In addition to initial investment in new routes and modes of transport, there has been substantial capital investment in modernizing and expanding infrastructure and vehicles, including:

rail electrification, which has taken place throughout the period under review, albeit with extended gaps mainly associated with the two world wars. Electrification began in the 1900s with suburban routes and, since the 1920s, has increasingly been extended to longer distance commuter and trunk lines;

expansion of the London underground, principally suburban extensions since the 1930s, with extended gaps between individually large projects, and the construction of new lines through central London since the 1960s;

highway construction and mass car ownership with some new highway construction and the beginnings of mass car ownership evident between the wars.