A recent U.S. government study, the largest case controlled study to date regarding DUI of cannabis, found that cannabis is not associated with increase crash risk once adjusted for confounding variables such as age, race, gender, and the presence of other drugs, including alcohol:
"This analysis shows that the significant increased risk of crash involvement associated with THC and illegal drugs shown in Table 3 is not found after adjusting for these demographic variables."
Further, they found that cannabis did not add to the crash risk for drivers under the influence of alcohol:
"As was described above, there was no difference in crash risk for marijuana (THC)-positive drivers who were also positive for alcohol than for marijuana (THC)-positive drivers with no alcohol, beyond the risk attributable to alcohol."
They found that alcohol significantly increased crash risk:
"at moderate alcohol levels (0.05 BrAC) risk increases to double that of sober drivers, and at a higher level (0.10 BrAC) the risk increases to five and a half times. At a BrAC of 0.15, the risk is 12 times, and by BrACs of 0.20+ the risk is over 23 times higher."
Re: “Vermont Officials to Take Pot Fact-Finding Trip to Colorado”
A recent U.S. government study, the largest case controlled study to date regarding DUI of cannabis, found that cannabis is not associated with increase crash risk once adjusted for confounding variables such as age, race, gender, and the presence of other drugs, including alcohol:
"This analysis shows that the significant increased risk of crash involvement associated with THC and illegal drugs shown in Table 3 is not found after adjusting for these demographic variables."
Further, they found that cannabis did not add to the crash risk for drivers under the influence of alcohol:
"As was described above, there was no difference in crash risk for marijuana (THC)-positive drivers who were also positive for alcohol than for marijuana (THC)-positive drivers with no alcohol, beyond the risk attributable to alcohol."
They found that alcohol significantly increased crash risk:
"at moderate alcohol levels (0.05 BrAC) risk increases to double that of sober drivers, and at a higher level (0.10 BrAC) the risk increases to five and a half times. At a BrAC of 0.15, the risk is 12 times, and by BrACs of 0.20+ the risk is over 23 times higher."