Marijuana, Driving and Impairment Tests presents the PhD project conducted by Dr Katherine Papafotiou in 2001. The project involved the administration of 3 doses of marijuana to drivers, and the assessment of driving performance and performance on impairment tests (Standardised Field Sobriety Tests- as used by Victoria Police, Australia). The introductory chapters of the book present previous research on the prevalence of marijuana use in the community, the prevalence of marijuana in road crashes and the effects of marijuana on driving performance. The book also takes a close look at the research on the accuracy of impairment tests to test for impairment caused by drugs. The results of the project demonstrate that marijuana impairs driving differently to alcohol and that impairment tests are moderately accurate tests of impairment caused by drugs. Dr Papafotiou makes some recommendations on how the accuracy of impairment tests, to test for the presence of marijuana and impairment in drivers, can be improved.