This thesis critically reviews the regulation of motor vehicles in Britain, and in particular the prosecution of drivers who kill cyclists and pedestrians. The development of road traffic regulation is discussed with particular emphasis on the social and legal processes at work behind the evolution of the law, and anomalies in the current laws are highlighted. The differential rights and responsibilities of drivers and vulnerable road users are considered within a conceptual framework which uses class- and power-based synthesis to explain demographic trends in car use and road casualties. A critical analysis of a set of court transcripts and newspaper reports involving road accidents then aims to discover whether those drivers who are convicted of killing vulnerable road users are less harshly punished than other criminals who cause death without intent. The thesis concludes by discovering that drivers are less harshly punished, and that this is due to a bias in the criminal justice system.