Missed opportunities?

A report published in December 2022 [1] concludes:

Multiple drugs and drug categories, including alcohol, cannabis and numerous illicit, prescription, and the over the counter drugs can impair driving performance and are associated with increased crash risk.

Alcohol, both alone and in combination with other drugs, continues to be the drug with the most detrimental impact on traffic safety.

Cannabis and other potentially impairing drugs, especially in combination with and without alcohol, contribute to the problem of impaired driving crashes due to their prevalence and negative impacts on driving performance.

Alcohol was the most prevalent drug found among impaired drivers in toxicology data reviewed by the National Transportation Safety Board, and about half of all impaired drivers were positive for other drugs or multiple drugs, indicating that although alcohol-related countermeasures must remain the highest priority, countermeasures that effectively address other drugs and drug combination are also needed.

This latter point highlights an issue that occurs in the UK too:

When a driver is apprehended for, say, a driving offence and then has a breath sample taken which is over the legal limit, the police force in question would then not normally pursue a drug-related contribution to the incident i.e. a driver would follow an alcohol-only route of prosecution.

The lack of drug testing of the individual means that valuable test data is not recorded.

Although, of course, a forensic scientist would always want a blood sample to be taken from everyone involved in a case!

[1] https://www.ntsb.gov/safety/safety-studies/Documents/SRR2202.pdf