A report released by the National Highway Traffic Safety Administration (NHTSA) puts into doubt the evidence behind per se THC driving limits.
According to the National Conference of State Legislatures, there are five states with per se THC driving limits – Illinois, Montana, Nevada, Ohio and Washington. These type of limits mean that if someone has over a certain about of THC in their blood – often either 2 or 5 nanograms per milliliter of blood – they are automatically guilty of driving under the influence of drugs (DUID). This is a clear issue given that, especially for regular marijuana consumers, THC can remain in the blood for days and sometimes weeks after last use.
Now, a report released by NHTSA says; “Several states have determined legal per se definitions of cannabis impairment, but relatively little research supports their relationship to crash risk. Unlike the research consensus that establishes a clear correlation between [alcohol content in blood] and crash risk, drug concentration in blood does not correlate to driving impairment.”
The report took note of research that “did not find a significant correspondence [between marijuana and accidents]”.
More information on this report, titled Memorandum and Review of Technology to Prevent Alcohol-and Drug-Impaired Crashes (TOPIC): Update” Report, can be found by clicking here.