Road casualties and public transport fares in London

In the light of effects of legal judgements upon implementation of its policies for reducing public transport fares, the Greater London Council became concerned that the higher fares it was obliged to introduce in 1982 would lead to a substantial increase in road casualties. When casualty figures began to bear out this fear, the Council commissioned an independent study at University College London in which various monthly data for the period January 1978-April 1983 were analysed in order to investigate relationships between numbers of casualties to various classes of road user and the levels of public transport fares in London. The specific objective of doing so was to estimate the size and statistical significance of such recent changes in numbers of road casualties in London as may have been associated with the large changes in London Transport fares which took place in October 1981 and March 1982. Log-linear regression models were fitted to casualty data for different classes of road user, and were used to estimate numbers of casualties that would have been expected, according to the fitted models, in the year May 1982-April 1983 if a near-doubling of fares that took place in March 1982 had not occurred, but instead the relatively low fares resulting from a reduction of about one-third in October 1981 had continued. The results indicated that several thousands fewer casualties would have been expected than actually occurred, most of the difference being among pedal cyclists and users of cars or taxis. A further fares reduction took place in May 1983, and data for the subsequent year are being used in a further study, which is also investigating various ways of improving and extending the models.