Dozens of cannabis companies in Colorado are using Adopt a Highway roadside signs to get around the state's strict limits on marijuana advertising.

Colorado's measure doesn't make any changes to the state's driving-under-the-influence laws, leaving lawmakers and police to worry about its effect on road safety.

Cannabis companies are using a loophole in Colorado’s strict limits on marijuana advertising by sponsoring state highways and putting their names on roadside signs.

Cannabis companies are using a loophole in Colorado’s strict limits on marijuana advertising by sponsoring state highways and putting their names on roadside signs. Currently, 51 cannabis dis… ...

Colorado’s anticipated marijuana report details youth usage, driving and crime over the last 5 years Youth usage has not gone up as feared, but driving fatalities involving cannabinoids are on ...

Nebraska, Kansas, New Mexico and other states neighboring Colorado see an uptick in marijuana traffic since the state made it legal.

In addition, Colorado police are being trained to better spot stoned drivers. In January, when marijuana sales began, about 15 percent of citations for impaired driving were for people high on pot.

And therein lies the challenge in determining whether marijuana legalization in Colorado has led to an increase in stoned driving.

DENVER — A set of laws to govern how recreational marijuana should be grown, sold and taxed was signed into law Tuesday in Colorado, where Democratic Gov. John Hickenlooper called the measures ...