There’s been an unexpected twist to the legalized marijuana story. It appears that the initial statistics coming out of Colorado indicate that, contrary to the dire predictions of those against legal pot, fatal crashes are actually down since Colorado legalized marijuana.

Another reason to doubt the premise that more pot smoking means more deadly crashes: Total traffic fatalities have fallen as marijuana consumption has risen; there were about 20 percent fewer in 2012 than in 2002. Perhaps fatalities would have fallen faster if it weren’t for all those new pot smokers. But there is reason to believe the opposite may be true, that there would have been more fatalities if marijuana consumption had remained level or declined.

The reasons for this are not entirely clear. But it seems that many people who would have been driving drunk are driving stoned instead. And the impairment to driving caused by marijuana intoxication is not as severe as that experienced with alcohol. Which has, apparently, resulted in fewer total DUI fatalities.

State and federal officials are wary about saying anything that would encourage people to drive while under the influence of any intoxicant, but even still, studies on the effects of marijuana on one’s capacity to drive have confirmed what marijuana proponents have been saying all along: alcohol is a far more dangerous drug than marijuana—at least statistically speaking:

A 1993 report from the National Highway Traffic Safety Administration, for example, concluded: “The impairment [from marijuana] manifests itself mainly in the ability to maintain a lateral position on the road, but its magnitude is not exceptional in comparison with changes produced by many medicinal drugs and alcohol. Drivers under the influence of marijuana retain insight in their performance and will compensate when they can, for example, by slowing down or increasing effort. As a consequence, THC’s adverse effects on driving performance appear relatively small.”

Statistics have a knack for being misleading. But one thing is for sure, marijuana is not as dangerous as opponents to legal pot have been saying. If Colorado is a test case for what would happen if marijuana were legalized nationally, there is a lot less to fear than was previously thought.