Utah cracks down on Cottonwood Canyons traffic: What you need to know about the new traction law

Like a set of studded snow tires, Utah’s traction law finally has some teeth.

Starting this season, the Utah Department of Transportation will be able to enact traction restrictions in Big and Little Cottonwood Canyon well before the arrival of a big storm. It will be able to tighten up traction requirements when roads become particularly treacherous.

And, for those still not willing to get snow tires, chains or other traction devices, officers will have the power to issue citations carrying fines of up to $750.

The additional measures are meant to reduce traffic congestion caused by slideouts and accidents on snowy days in the two winding canyons, each of which is home to two of Utah’s most popular ski and snowboarding areas. UDOT announced the changes and the return of its popular Cottonwood Canyons Sticker Program during a press conference Thursday.

“These updates make sure drivers have the right equipment before heading into the canyons, even if a storm rolls in while they’re parked,” UDOT Region Two Director Robert Stewart said in a statement. “We hope this gives everyone more peace of mind knowing they, and the drivers around them, are ready for winter conditions.”

Why are traction requirements different this winter?

The population of the Wasatch Front has swelled in recent decades, as has the popularity of skiing and snowboarding in the Cottonwood Canyons. The result has been the growth of the Red Snake — a pejorative term for a long line of automobile tail lights — on weekends and seemingly any day it snows.

Often, the cause of what can be hours-long delays can be traced back to vehicles ill-equipped to drive in icy or snowy conditions. Yet because the traction requirement is technically a UDOT rule, not a law, the agency and law enforcement officers have historically had few tools to take such cars off the road.

That changed this spring when state legislators passed a law that clarified two things. One was that UDOT can preemptively require traction devices in the Cottonwood Canyons up to 24 hours in advance. The second was that when the traction law is enacted, drivers of vehicles without adequate tires or gripping devices — such as chains or snow socks — can be ticketed. Previously, officers were unclear whether they could ticket drivers with inadequate tires if they were not involved in a crash.

What are the traction requirements?

When traction devices are required, UDOT will activate the flashing lights attached to traction signs at the mouth of the canyons. Additionally, the agency posts alerts on its social media channels.

At that time, vehicles are not allowed to be on the road unless they have proper tires or traction devices. This season, those include: mud-and-snow (M+S) or 3-peaks (3PMSF) tires on four-wheel-drive and all-wheel-drive vehicles or 3-peaks tires, chains or snow socks for vehicles with two-wheel-drive.

New this winter, UDOT has implemented a “Class Three” designation that currently only applies to the Cottonwood Canyons. It further requires that, when the traction law is in effect, only vehicles with a tread depth of 5/32 inch or greater — as well as proper traction — will be allowed in the canyons. (Utah law requires all vehicles, regardless of season, to have a tread depth of 2/32 inch or greater).

The good news for anyone without a tread gauge is that 5/32 inch is also the minimum amount of tread a vehicle needs to qualify for UDOT’s Cottonwood Canyons Sticker Program. Drivers can get their tires checked for free at any one of 140 tire shops throughout the Wasatch Mountain range through Feb. 28. If the tires meet UDOT’s traction standards, the vehicle will receive a sticker that should allow it to pass through any canyon-mouth traction check unimpeded.

Chris McHugh, the assistant chief of the Cottonwood Heights Police Department, said that agency plans to set up an express lane for vehicles with UDOT’s stickers during traction checks. Cottonwood Heights officers patrol the mouth of Big Cottonwood Canyon.

“With the ability to slow the cars down and check the cars, we’re cutting down on the amount of traffic and crashes and slide offs that happen in the canyon,” McHugh said, “which is cutting down on the sheriff’s work and Unified Police’s work up in the top of the canyons.”

Additionally, cutting down on accidents in the canyons reduces closures of Big Cottonwood Canyon Road, which he said reduces congestion in the communities at the bottom of the canyon.

Last winter, UDOT issued about 22,000 stickers. This year, a spokesperson said the agency had 35,000 printed.

“Powder panic is a real thing. We know this,” said Jacob Marquardt, a spokesperson for Snowbird resort in Little Cottonwood Canyon. “On those days, when it seems like everyone and their mom is trying to get up the canyon, it’s really wonderful to have UDOT and the Unified Police and the sheriffs implementing the sticker program at the base of the canyon, because it makes the road safer and it reduces congestion, which is going to just get people on the slopes sooner.”

Bruce Hill of Sandy was among the first to get a 2025-26 sticker. He waited patiently in the two-lane line at UDOT’s Cottonwood maintenance shed in his red Dodge Ram. He said he thinks driving a truck had helped him avoid traction checks in previous years.

Last year, worried his luck might run out, he got his first sticker. Now he was back for another. They haven’t helped with congestion, Hill said, but they might.

“I’m a skier,” he said, “I’m just doing it so I can get up the canyons faster.”

UDOT Cottonwood Canyon Sticker Program Requirements