Utah's Canyon Traction Law: A Simple Guide for Skiers
A complete guide to Utah's traction law for Little and Big Cottonwood Canyons. Learn what tires you need (4WD/AWD/2WD) and how to check the live status before you go.
Utah's Traction Law is a safety rule for driving in the Cottonwood Canyons during winter storms. When activated, it requires all vehicles to have specific snow-rated tires or chains to prevent accidents and keep the roads open. This guide explains what you need for your vehicle to be compliant so you can get to the ski resorts safely.
What is the Utah Traction Law?
When winter weather hits Little and Big Cottonwood Canyons, the Utah Department of Transportation (UDOT) can activate the Traction Law. This is a legal requirement designed to ensure every vehicle on the steep, winding roads has enough grip to travel safely. When the law is in effect, electronic signs at the canyon mouth will alert drivers, and law enforcement will turn away any vehicles that don't meet the specific tire requirements.
Ignoring the law doesn't just put you at risk—it endangers everyone. A single car spinning out can create canyon-wide gridlock, stranding skiers, commuters, and even emergency vehicles for hours. Complying is your ticket to a smooth, safe trip and a shared responsibility for keeping the canyons accessible for everyone.
Why It Matters for Canyon Travel
Following the Traction Law isn't just about avoiding a fine; it's about mountain safety.
- It Prevents Accidents: The right tires or chains provide the grip you absolutely need on steep, slick inclines.
- It Avoids Road Closures: Fewer spinouts and accidents mean the roads stay open for everyone trying to enjoy Alta, Snowbird, Brighton, or Solitude.
- It Keeps You Moving: Being prepared means you won't get turned around at a checkpoint.
Based on live data from the 2022-2023 season, the traction law was implemented 71 times in Little Cottonwood Canyon. Being unprepared is the leading cause of traffic jams and accidents during these periods. The wrong tires on a two-wheel-drive car or worn-out all-seasons on an AWD vehicle can turn a powder day into a frustrating and dangerous ordeal.
When and Where is the Traction Law Enforced?
The Traction Law is a dynamic safety measure that UDOT activates only when road conditions become hazardous due to snow or ice. This isn't a year-round rule; it's triggered specifically by winter storms to manage the unique dangers of the Cottonwood Canyons.
Which Roads Are Affected?
The law is laser-focused on the two main arteries feeding the central Wasatch ski resorts:
- Little Cottonwood Canyon: Enforced on State Route 210 (SR-210), the only road to Alta and Snowbird.
- Big Cottonwood Canyon: Enforced on State Route 190 (SR-190), the only road to Solitude and Brighton.
When a storm rolls in, UDOT and the Unified Police Department (UPD) set up checkpoints at the mouths of the canyons. If your vehicle isn't compliant, you will be turned away—no exceptions.
How to Check the Live Status
Knowing the law’s status before you leave home is the most important part of your trip plan. Waiting until you see the road signs is too late.
- UDOT Traffic Website: The official site, udottraffic.utah.gov, is your most reliable source. It features a live map with alerts and traction law notifications for SR-210 and SR-190.
- UDOT Traffic App: Available for iOS and Android, this app provides real-time info and push notifications for your route.
- Local Resources: Our Little Cottonwood Canyon conditions and Big Cottonwood Canyon conditions pages provide a focused snapshot of the live traction law status, road conditions, and traffic.
Local Tip: Always check one of these resources right before you get in the car. Conditions change rapidly, and the law can be activated with little warning.
How to Meet the Tire Requirements
Getting up the canyons safely starts with your tires. The traction law has specific rules about tire type and tread depth, which vary based on your vehicle's drivetrain (4WD/AWD vs. 2WD).
What Do the Tire Symbols Mean?
Law enforcement will check your tire's sidewall for one of two symbols:
- M+S (Mud and Snow): Found on most all-season tires, this indicates the tread is designed for better performance in light snow than a summer tire. This is a manufacturer's self-reported rating.
- 3PMSF (Three-Peak Mountain Snowflake): This is the gold standard. The symbol means the tire has passed a rigorous, standardized test for severe snow service. It is a certified winter tire.
What Do I Need for My Vehicle?
| Vehicle Type | Required Equipment | Is This Compliant? |
|---|---|---|
| 4WD/AWD | Tires with M+S or 3PMSF symbol and at least 5/32" tread depth. | Yes |
| 2WD | Tires with the 3PMSF symbol and at least 5/32" tread depth. | Yes |
| 2WD | Tires with the M+S symbol and at least 5/32" tread depth. | No (Chains are required) |
| Any Vehicle | Tire chains installed on drive tires. | Yes |
| Any Vehicle | Summer tires, regardless of tread depth. | No |
Key Takeaway: 4WD/AWD vehicles have more flexibility, but 2WD vehicles must have 3PMSF-rated tires or use chains to be compliant. M+S tires alone are not sufficient for 2WD vehicles.
Local Tip: You can check your tread depth with a penny. Stick it in the tread with Lincoln's head down. If you can see the top of his head, your tread is likely below the required 5/32" and is not compliant.
What Happens if I'm Not Compliant?
Ignoring the traction law carries serious consequences beyond just being turned around. Fines for non-compliance can be hefty, but the real penalty comes if your vehicle causes an accident or road blockage.
If your non-compliant vehicle blocks a canyon road, you can be held liable for the full cost of the closure. This includes towing, road cleanup, and personnel time, which can easily run into thousands of dollars.
Following the rules is a sign of respect for other drivers, resort employees, and the first responders who work to keep the canyons safe. A little preparation ensures a safe day for the entire community.
Traction Law FAQ
Are rental cars exempt from the Traction Law?
No. Rental cars must follow the same rules. When booking, specifically request a 4WD/AWD vehicle with M+S or 3PMSF tires. Most rental agencies forbid the use of chains, so having the right tires is critical.
I have a 2WD car with M+S tires. Can I go up?
No. This is the most common mistake. A 2WD vehicle with only M+S tires is not compliant. You must either have 3PMSF-rated tires on all four wheels or install chains on your drive tires.
What if the law is enacted while I am already at the resort?
You must still be compliant for the drive down. This is why it's crucial to be prepared for winter conditions for your entire trip, not just the morning drive up. Carry chains in your vehicle even if the law isn't active when you ascend.
You can find more answers to frequently asked questions on our site to help you prepare for any situation in the canyons.