A drumbeat of dire warnings sounded across Colorado and Washington as its voters moved toward to legalizing recreational marijuana in 2012, becoming the first states in the U.S. to do so. Opponents had argued that a surge in blazed drivers would litter the roads and highways with bodies. They also claimed that more children would devolve into budding young stoners.

Those doomsday scenarios have yet to materialize, data shows.

Recreational weed has had negligible effects over the rates of traffic fatalities and youth marijuana use in Colorado and Washington, according to a new report by the Drug Policy Alliance, an advocacy group that promotes progressive drug reform laws. Early research compiled by the organization also shows that marijuana consumption rates among children in Alaska, Oregon, and Washington, D.C. — which have since approved recreational weed — remain virtually unchanged as well.

The findings come as voters in another five states — Arizona, California, Massachusetts, Nevada, and Maine — weigh whether to adopt similar recreational marijuana measures next month. While the data is still preliminary, given recreational weed’s short existence in only a handful of states, it remains encouraging for pro-pot advocates.

“This report shows that a lot of those fears don’t come to fruition in the case of legalization,” Joy Haviland, a staff attorney with the DPA, told the Huffington Post. “It’s clear that prohibition has not worked, so states need a new solution going forward.”

According to the report, legal weed has had no discernible impact on traffic fatalities in Colorado and Washington. In fact, both states continue to have fewer reported road deaths than the national average, data shows. While some recent studies have shown that more Washington state drivers involved in fatal crashes have tested positive for THC, the psychoactive compound found in marijuana, a clear link between impairment and THC levels remains unestablished scientifically, the DPA argues.

The group’s study also examined surveys of high school student marijuana use conducted in Alaska, Colorado, Oregon, and Washington. No state survey revealed a significant change, positive or negative, in cannabis consumption among students since legalization, the study shows.

Read the rest of the Drug Policy Alliance’s study here.