DENVER (AP) — "Friends don't let friends drive I-70."
The tongue-in-cheek mantra is often uttered by Colorado skiers and snowboarders who frequent resorts far from the crowded mountain corridor, which funnels thousands of vehicles onto two lanes west of Denver every winter weekend.
"It's nightmarish. Hours and hours in the car. I think the last time I went to Keystone (typically a 90-minute drive from Denver), I spent four hours getting there and five hours getting home," said Cole Capsalis of Denver. "There was more time in the car than skiing."
The 28-year-old product manager, who went to the University of Utah in part because it allowed him to hit the slopes up to 100 days a year, moved to Denver about six years ago. But his love of ski resorts quickly took a tumble because of horrendous traffic more akin to Los Angeles freeways.
So Capsalis ditched resorts for less crowded — albeit more dangerous — remote backcountry snowboarding.
"I would prefer to risk my life on some level ... as opposed to sit in I-70 traffic on the weekends," he said.
Traffic along the route has been common for years, but it's exacerbated by a recent population boom in the Denver area.
"Traffic has increased incredibly statewide, and nowhere do you see that more actively than on the I-70 corridor," said Amy Ford, a state transportation department spokeswoman.
Between 2010 and July 2017, the population in Denver and its suburbs increased by an average of nearly 51,000 annually.
In 2000, nearly 10.3 million vehicles on I-70 crossed the Continental Divide, which slices through the heart of Colorado's ski country. That figure was about 13.4 million in 2018.
"It's always going to get worse. We're expecting that," said Patrick Chavez, who works at a transportation department office at the mouth of two tunnels bored under the Divide. "We continue to try to find measures to mitigate and minimize the impact."
But that's getting harder as more people move to Colorado, he said.
Colorado's population has increased 53 percent since 1990, while lane miles on the state's highway system have only increased 2 percent, officials said.
The department's typical $1.4 billion budget, 70 percent of which goes toward road maintenance, is only slightly bigger than neighboring Utah's. But Colorado has 6,864 more highway lane miles (11,046 kilometers) and 2.4 million more residents.
Unlike Utah, Colorado doesn't dip into sales tax to fund its transportation budget, and its state gas tax, the 12th lowest in the country, hasn't been raised since George H.W. Bush's presidency.
High-speed rail could be built through the corridor, but may cost between $11 billion and $32 billion depending on the route and type of train used, according to a 2014 study commissioned by the transportation department.
The three viable options would require significant right-of-way acquisition, and crews would have to blast between 15 and 35 tunnels. A train on the existing right-of-way would have to travel so slowly on the interstate's curves and grades that it couldn't compete with driving.
That means transportation officials will continue to rely on smaller-scale solutions to an increasingly difficult problem.
They're quicker at clearing accidents. They've installed traffic information signs at resorts and in-pavement LED lighting on areas of the interstate with poor visibility. They've widened tunnels and introduced a bus system that runs on I-70. And they've built a 13-mile (21-kilometer) toll road at a notorious pinch point on eastbound I-70.
All those steps, Ford said, have had a positive effect and reduced the number of accidents.
In 2008, nearly 1,900 accidents were reported along the corridor and in 2017, about 1,200 accidents were reported.
The transportation department also is doing a relatively good job of keeping traffic flowing through the roughly 100-mile (161-kilometer) stretch that serves major resorts like Vail, Breckenridge and Keystone.
In January 2012, for example, it took drivers an average of an hour and 50 minutes to travel west through that section during the peak of weekend traffic. The numbers fluctuate through the years for a variety of reasons, including weather, but by January 2018, it took just over two hours.
Traveling that stretch without traffic typically takes 90 minutes.
"It is a significant challenge, but that corridor is getting a lot better," Ford said.
Still, words and numbers might not be enough to convince those who love to loathe I-70, and the department's biggest challenge could be battling the perception that the interstate is getting exponentially worse.
"I watched it deteriorate so much ... that I would have a really hard time believing that anything significant would have changed at this point," Capsalis said.