Road crash injuries higher in US states with legal cannabis

Recreational drug users may feel that driving while high is allowed after rule change, researchers say

INJURIES suffered in traffic accidents increase in areas where cannabis is legalised, research has found.

An investigation by the Insurance Institute for Highway Safety (IIHS) in Virginia identified that the number of crashes that caused injuries rose an average of a 5.8 per cent, and fatal accidents 4.1 per cent, in five US states that allow the recreational use of marijuana.

Colorado had the biggest increase in injury accidents – 17.8 per cent– while California had the smallest – 5.7 per cent. The researchers found no increase in a group of states that had not legalised the drug.

There were also increases in fatal road traffic accidents in Colorado and Oregon although other states, such as Nevada and Washington, registered falls, which researchers believe may be to do with a change in behaviour of intoxicated drivers.

Researchers said that drivers under the influence of marijuana often slow down and maintain a larger distance between themselves and other vehicles.

While this can lead to the avoidance of fatal accidents, dangerous collisions are caused by impaired drivers.

“The legalisation of marijuana doesn’t come without cost,” said Dr Charles Farmer of the IIHS, the lead

‘We need to convince everyone that driving under the influence of marijuana is not OK’

researcher. “Users who previously avoided driving high may feel that it’s OK after legalisation. We need to convince everyone that driving under the influence of marijuana is not OK. Then, enact laws and sanctions penalising those who ignore the message.”

For the study, researchers collected data on traffic crashes and traffic volume between 2009 and 2019 from 11 states and from the Federal Highway Administration.

The research, published in the Journal of Studies on Alcohol and Drugs, compared Colorado, Washington, Oregon, California and Nevada, which had legalised recreational marijuana, and compared them with Arizona, Idaho, Montana, New Mexico, Utah and Wyoming, where the drug remains banned.

Previous studies using driving simulators have shown marijuana use affects reaction time, lane discipline and attention, although it has been difficult to establish at exactly what level of intoxication the drug causes problems.

Driving while under the influence can also induce panic attacks and alter users’ sense of time, making the world appear slower than it is.

A Canadian study found that 13 per cent of cannabis users with a driving licence reported driving within two hours of consuming the drug and estimated legalisation could increase road fatalities by 300 per year.

In the US, 19 states have legalised cannabis, and Sadiq Khan, the London Mayor, visited Los Angeles to gauge the drug’s impact before launching a commission looking into its possible decriminalisation.