With the legalization of marijuana in Colorado and elsewhere, the question arises as to whether there is an associated increase in driving while under the influence of marijuana. However, the answer may not yet be clear.
People understand the dangers of driving while under the influence of alcohol fairly well. Are people now engaging in driving while high more than they did before marijuana use became legal, similar to alcohol?
According to USA Today, over the past 10 years, fatalities from motor vehicle accidents involving at least one drugged driver have doubled. The increase in such accidents appears to correlate with an overall movement throughout the United States to legalize marijuana. Colorado’s highway safety manager notes that the state’s decision to legalize the drug has most likely caused an increase in fatalities in Colorado. However, not everyone agrees.
Colorado has seen an increase in drugged driving
Notably, however, 30 percent of fatalities have a nexus to drunk driving, which remains far above the rate for drugged driving fatalities. Still, there is significant worry because those states like Colorado that have legalized marijuana have seen a notable increase in drugged driving incidents.
The Colorado Department of Transportation reported that in 2013, slightly more than 8 percent of the state’s deadly crashes involved a driver testing positive specifically for marijuana use. Two years later, however, that percentage rose more than 50 percent to exceed 12 percent of fatal crashes. Similarly, with regard to all drug-related vehicle accident fatalities, in 2012, less than 13 percent involved drivers testing positive for any drug. Two years later, that percentage rose to nearly 19 percent.
Placing blame for increased drugged driving is unclear
Proponents of the legalization dispute that there is adequate proof that legalization has had a negative effect on highway safety. There is a notable scarcity of research on the effects of drugs on a person’s driving ability, which limits the understanding of the true effects of drugged driving on road safety. Moreover, many drivers in deadly crashes never undergo a test for drugs. Also, marijuana may show up in blood tests weeks after its consumption, yet its strongest effects have long since disappeared.
Lastly, there is no universally accepted field sobriety test for marijuana impairment, unlike for alcohol. One study, however, revealed that while measuring THC, drivers with blood concentration of 13.1 ug/L of THC engaged in more weaving when driving, in a manner similar to a driver hitting the illegal alcohol limit of 0.08 percent.