Forensic science, expertise and evidence at the boundary of legislation, policy and politics: a case study of legislative, political and policy responses to the effects of drugs on road safety in Victoria and other Australian states

[Truncated abstract] In 2003 the Australian State of Victoria became the first jurisdiction in the world to allow random roadside testing of drivers for the presence of the illicit drugs cannabis and methamphetamine, using oral fluid testing technology. The implementation of The Road Safety (Drug Driving) Act 2003 in Victoria, and similar legislation adopted later by other Australian States, was accompanied by media campaigns that publicised the potential risks to road safety due to drug use, and aimed to deter driving after the consumption of methamphetamine or cannabis by promoting the certainty of apprehension. This publicity often made claims about risk and the effectiveness of the legislative countermeasures, based on scientific information that appeared as consensus statements or unequivocal messages. However, the science of toxicology, pharmacology and analytical chemistry, although necessary for the policy process that led to the legislative intervention, is insufficient to explain or justify it. Significant scientific uncertainty persists regarding the extent of the problem posed by the effects of illicit drugs and legal medications on driving impairment, the magnitude of alleged increases in risk of accident associated with driving after consuming these drugs, and methods for assessing impairment and detecting drug use. Extensive scientific literature has emerged in the past century regarding the effects of alcohol on road safety, upon which, effective drink-driving deterrence countermeasures such as random breath testing have been based. However, academic literature on similar effects and potential countermeasures for other drugs is incomplete and contradictory and this evidence has been selectively utilised. This thesis elaborates boundary interactions between forensic science, expertise, and evidence, and legislation, policy and politics by using a critical theory approach. Commonly-held assumptions about the nature of science, and the involvement of science with society, could restrict a comprehensive elaboration or illumination of the policy process that led to the roadside drug testing legislation. A traditional positivist perspective may be empirically and normatively challenged by broadening theoretical perspectives to include more interpretive views of science. This is especially important when the framing of risk-related problems, as well as preferred solutions to those problems, are based on value-laden, and culturally-grounded beliefs held by politicians and their constituents, policymakers and scientists. Extensive analysis of documentation, parliamentary debates and media, as well as a set of semi-structured interviews with key participants involved in the various strands leading to the 2003 legislation in Victoria and other states in Australia, provided data for illuminating this policy process...