Spring break in the mountains: the risks of impaired driving at altitude

Statewide — As thousands of visitors travel to Colorado’s ski resorts for spring break, the Colorado Department of Transportation (CDOT) urges mountain-goers to plan ahead to avoid impaired driving. The effects of higher altitude on the body — which include dehydration, tiring more easily and less oxygen — can potentially increase impairment. That means even moderate consumption of cannabis or alcohol can lead to a stronger impact than expected.

There were 203 fatalities on Colorado roads in 2024 that involved an impaired driver, accounting for 31% of all traffic deaths during the year. Last year, law enforcement agencies in Eagle and Summit counties issued more than 120 DUIs between February and April during impaired driving enforcement periods.

"We're reminding visitors that much like skiing, driving demands your complete attention and focus," said Sam Cole, CDOT Communications Manager. "A drink or edible that feels mild at sea level can have a stronger effect in the mountains. For spring breakers, this can lead to risky behaviors, including getting behind the wheel while impaired. We want everyone to enjoy their spring break responsibly and make smart choices."

If a person’s ability to operate a vehicle is affected to the slightest degree, drivers can be arrested and cited for DUI or DWAI if law enforcement observes and documents driver impairment, even with a blood level below 5 ng of Delta 9 THC or .05 in a breath or blood test for alcohol detection.

"Every year, we see a spike in DUIs during spring break, many of which involve visitors who underestimate altitude's impact on alcohol impairment and the potency of cannabis products," said Summit County Sheriff Jaime FitzSimons. “We want everyone to stay safe while enjoying the mountains. Please plan ahead, make responsible choices, and don't put yourself or others in danger."

Acute Mountain Sickness, also known as altitude sickness, has an estimated occurrence of around 25% among out-of-state visitors to Summit County.

CDOT emphasizes that combining alcohol and cannabis, otherwise known as polyconsumption, slows reaction time, impairs judgment and distorts the perception of time, distance and speed. The effects make driving extremely dangerous — especially on winding mountain roads, where visibility and conditions can change rapidly.

If you’re headed to the mountains this spring break, CDOT encourages travelers to:

• Recognize that driving while high or impaired is illegal and dangerous.
• Understand that altitude, dehydration and unfamiliarity with cannabis products can amplify impairment, especially for out-of-state visitors.
• Designate a sober driver or wait until safely at their final destination before legally consuming cannabis.
• Enjoy the mountains responsibly and avoid ruining their vacation with a DUI, serious injury or fatality.

Colorado's mountain communities offer robust public transportation and ride services for those seeking safe alternatives to driving impaired. Visitors can use bus systems, shuttle services and ride-sharing options to and from the slopes and while traveling around Colorado's high country. For information on public transportation schedules and routes, visit goi70.com/transit.

CDOT’s Approach

CDOT is taking a no-opportunity-left-behind mentality when it comes to reaching consumers and reducing impaired driving-related fatalities.

CDOT’s Meet The Effects awareness campaign will be active in broadcast, digital, print and out-of-home media from April to June. The campaign educates consumers about cannabis-impaired driving by personifying how cannabis negatively impacts driving performance and the consequences of impaired driving. For information and resources on cannabis-impaired driving, visit CDOT’s DriveHighDUI.com website. Additionally, CDOT has partnered with Learn Brands, an online budtender education platform, to provide a free interactive cannabis-impaired driving safety course. Take CDOT’s Budtender Training Course.

The CDOT Highway Safety Office provides funding to Colorado law enforcement for impaired driving enforcement, education and awareness campaigns. The Heat Is On campaign runs throughout the year, with 16 specific high-visibility impaired driving enforcement periods centered on national holidays and large public events. Enforcement periods can include sobriety checkpoints, saturation patrols and additional law enforcement on duty dedicated to impaired driving enforcement. Find more details about the campaign, including impaired driving enforcement plans, arrest totals and safety tips, at HeatIsOnColorado.com. More information about DUI laws in Colorado can be found at NoDUIColorado.org.

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