This Valentine’s Day, the Colorado Department of Transportation is in love with drivers who follow the law.

On Feb. 13 and 14, CDOT will hand out cannabis-themed safety bouquets and valentines at the metro Denver locations of Lightshade, a dispensary company. The giveaways are a reminder to avoid driving impaired, and a product of the department’s two-year “Cannabis Conversation” initiative.

CDOT solicited the perspectives of 18,000 Colorado residents about cannabis-impaired driving, and found that people who drive after getting high expect their passengers to intervene if they feel unsafe. However, passengers reported not feeling comfortable speaking up. CDOT hopes the bouquets and valentines will remind people to speak up about their loved ones’ impairment.

While there is no roadside device to measure blood levels of tetrahydrocannabinol, the psychoactive ingredient in marijuana, law enforcement officers decide whether to arrest a driver based on observed impairment. Drivers with five nanograms of active THC in their blood can be charged with driving under the influence, leading to potential jail time or loss of license.

Between 2016 and 2018, the proportion of marijuana users who reported driving two to three hours after consumption increased by 11%, to more than one in five users. However, in that same time period, cannabis-involved vehicle fatalities have dropped by 40%, from 52 in 2016 to 31 in 2018.

Sam Cole, a spokesperson for CDOT, attributed the decline to a public awareness campaign and officers being trained to identify impaired drivers before they crash.

“However, three years does not make a trend,” he added. “We will continue to address the problem as we have in the past. We would like to see several more years worth of data.”

Editor’s note: This story has been updated with comment from CDOT.