Between January 2008 and December 2018 in South Australia MA was found in 28/300 (9%) of driver deaths.
Between January 2008 and December 2018 in South Australia blood alcohol >0.05 g/100 ml was found in 115/300 (38%) of driver deaths.
Although numbers of alcohol positive cases declined significantly (p < 0.001), no change occurred in numbers of MA positive cases.
While roadside breath testing, legislative changes, and increase monitoring have reduced drunk driving, this has not affected MA users.
Motor vehicle driver fatalities (>18 years) from the files at Forensic Science South Australia were reviewed from January 2008 to December 2018 for cases in which either positive blood sample for methamphetamine (MA) or an illegal blood alcohol concentration (BAC) >0.05g/100mL were found. 300 driver deaths were found with MA detected in 28 cases (age range 21-62 years; ave. 37.8 years; M:F 23:5). 115 cases with a BAC>0.05g/100mL were identified (age range 18-67 years; ave 35.7 years; M:F 95:20). No change was found in numbers of MA cases, although alcohol cases showed a significant decline (p<0.001). Drunk driving-related fatal crashes tended to occur in the evening (5pm to 11pm), whilst MA-related fatal crashes had a longer peak extending from late evening until late morning (11pm to 8am). This study has demonstrated that while roadside breath testing, legislative changes and increased monitoring have resulted in reduced levels of drunk driving, similar safety countermeasures have had negligible effects on MA use in drivers. Continued monitoring of MA use by drivers will, therefore, be necessary to assess the possible effects, or not, of new countermeasures.