# Colorado's Traction Law: What Families Driving to the Slopes Need to Know

> Source: Snowthere.com
> URL: https://www.snowthere.com/guides/colorado-traction-law-families
> Type: how-to guide
> Last Updated: 2026-08-15T05:23:30.49041+00:00
> Category: driving

## Summary

Colorado's Traction Law goes up on overhead signs while you are already driving, and all-wheel drive alone does not satisfy it. Here is what the rule actually asks of a rented SUV, how to check the tread in the airport car park, and what the two published fines are for.

## Overview

You are somewhere west of Denver in a rented SUV. The snow started twenty minutes ago, two kids in the back are asking how much longer, and an overhead sign tells you the Traction Law is in effect . Nobody at the rental counter mentioned it. You have no idea what tyres are on this car. The answer first, because you are probably reading this at 11pm the night before: an all-wheel-drive rental can comply, but not because it is all-wheel drive . Every route on Colorado's list that is not chains ask...

## Comparisons

### Colorado is not Utah, and Utah is not California

| Rule, as published | What the official page asks of a family car | Minimum tread on that page | Published penalty |
| --- | --- | --- | --- |
| Colorado Traction Law | Four routes: AWD or 4WD with tyres marked M+S or carrying the mountain-snowflake icon; two-wheel drive with those same tyres; a manufacturer all-weather rating; or chains or an approved alternative traction device. The page does not name 3PMSF certification | 3/16 inch, which is 6/32, on all three tyre routes | $100 plus a $33 surcharge; $500 plus a $157 surcharge where failing to comply resulted in a road closure of a travel lane in one or more directions |
| Colorado Passenger Vehicle Chain Law | Every vehicle must have chains or an approved alternative traction device. No tyre route at all | Not applicable, the requirement is the device itself | As above. CDOT's page calls this the final measure before the highway is closed |
| Utah, UDOT Class 2 | AWD/4WD: M+S or 3PMSF tyres on all wheels is the minimum. 2WD: 3PMSF tyres on all wheels, or traction devices on at least two drive wheels | Not stated on the UDOT page we checked | Not published on the UDOT page we checked, so we are not quoting a figure |
| California, Caltrans R2 | 4WD/AWD is excused from fitting chains only with snow-tread tyres on all four wheels, and must still carry chains or traction devices in the control area | Not stated on the Caltrans page we checked | Caltrans says you can be cited and fined but publishes no dollar figure on that page |
| Washington, RCW 47.36.250 | An approved traction tyre means an aggressive tread pattern plus an M+S or mountain snowflake marking | 4/32 inch | $500 flat, including all statutory assessments, on the page we read in August 2026 |

## Key Recommendations

### The four ways to satisfy the Traction Law

- **All-wheel or four-wheel drive with qualifying tyres**: CDOT's first route pairs an AWD or 4WD vehicle with tyres marked <strong>M+S or carrying the mountain-snowflake icon</strong>, and <strong>3/16 inch of tread depth</strong>. Read that twice. The drivetrain is one half of the condition, not the whole of it.
- **Two-wheel drive with those same tyres**: This is the route families assume does not exist. On CDOT's traction law page, read in August 2026, a two-wheel-drive vehicle also complies with tyres carrying those same markings and the same 3/16 inch of tread. A front-wheel-drive rental is not automatically out of the running. Its tyres decide, exactly as they do for the SUV.
- **A manufacturer all-weather rating, with the same tread depth**: The third route drops the sidewall marking and accepts an all-weather rating given by the tyre manufacturer, still with at least 3/16 inch of tread. The tread number is the one constant across all three tyre routes.
- **Chains, or an approved alternative traction device**: The route that works regardless of which car you were handed at the counter, and the only route left once the Chain Law goes up. Check CDOT's own page for which alternative devices are approved before you spend money, because "traction device" is a category, not a product.

## Checklists

### Before you leave the rental counter in Denver

- [ ] Crouch at a front tyre and find either an M+S marking or the mountain-snowflake icon on the sidewall, or confirm the tyres carry a manufacturer all-weather rating. If none of those is there, chains are your only route on CDOT's list, whatever the drivetrain.
- [ ] Measure the tread in at least two grooves per tyre. Colorado wants 3/16 inch, which is the same as 6/32 inch.
- [ ] If the tread is marginal, ask for a different vehicle at the desk. This request is far cheaper in the car park than on a pass.
- [ ] Do not assume a two-wheel-drive car is disqualified. CDOT's page, read in August 2026, gives it the same tyre route, with the same markings and the same 3/16 inch of tread.
- [ ] Ask whether your rental contract permits fitting chains or an approved alternative traction device to the car.
- [ ] Decide whether you are carrying chains before you leave. The Passenger Vehicle Chain Law removes every tyre route, and CDOT's page calls it the final measure before the highway is closed.
- [ ] Check CDOT's own page for which alternative traction devices are approved before buying anything described as a chain substitute.
- [ ] Put gloves, a head torch and a phone battery pack in the cabin, not in the boot under the ski bags.
- [ ] Practise fitting chains once at home in daylight, so the first attempt is not in a storm with children in the back.
- [ ] Pack water, snacks and a blanket within arm's reach of the back seat. A closure is a waiting problem before it is a driving problem.
- [ ] Check road conditions before every mountain leg of the trip, not just on arrival day. CDOT's page states these laws may be implemented on any state highway, including the small road at the end.

## Frequently Asked Questions

**Q: Does an AWD rental car automatically meet Colorado's Traction Law?**
A: No. On CDOT's traction law page, read in August 2026, the tyre routes ask for tyres marked M+S or carrying the mountain-snowflake icon, or a manufacturer all-weather rating, and at least 3/16 inch of tread depth in every case. All-wheel drive on unmarked or worn tyres is not compliant, and a two-wheel-drive car with the right markings and enough tread has its own route on the same list. Under the Passenger Vehicle Chain Law, all-wheel drive earns you no exemption at all, because every vehicle must then carry chains or an approved alternative traction device.

**Q: How do I check whether my tyres have 3/16 inch of tread?**
A: 3/16 inch is the same as 6/32 inch, which matters because tyre gauges and tyre shops usually talk in thirty-seconds while CDOT writes the requirement in sixteenths. A tread depth gauge is the reliable way to get an actual number, and it fits in a coat pocket. Measure several grooves on each tyre, because tread wears unevenly and you want your worst reading rather than your best one. If you cannot measure it, you do not know it, and the rental desk is the cheapest place to fix that.

**Q: What is the difference between the Traction Law and the Chain Law in Colorado?**
A: The Traction Law gives you four routes on CDOT's list: an AWD or 4WD vehicle with tyres marked M+S or carrying the mountain-snowflake icon, a two-wheel-drive vehicle with those same tyres, a manufacturer all-weather rating, each of those three with at least 3/16 inch of tread, or chains or an approved alternative traction device. The Passenger Vehicle Chain Law is stricter: every vehicle must have chains or an approved alternative device, with no tyre route at all. CDOT's page describes the chain law as the final measure before the highway is closed.

**Q: What is the fine for breaking Colorado's Traction Law?**
A: As published by CDOT and checked in August 2026, non-compliance carries a $100 fine plus a $33 surcharge. Failing to comply with restrictions in a way that resulted in a road closure of a travel lane in one or more directions can carry a $500 fine plus a $157 surcharge. The larger amount is tied to that closure, not simply to being stuck, and it reflects what a closed lane does to everyone behind you on a mountain highway. Fine schedules are revised periodically, so confirm current figures with CDOT before you travel.

**Q: Do I have to buy chains for a Colorado family ski trip?**
A: Not to satisfy the Traction Law, if your car's tyres already qualify, and that holds whether the car is all-wheel drive or two-wheel drive. But chains or an approved alternative traction device are the only way to comply once the Passenger Vehicle Chain Law is in effect, and that can be declared while you are already driving. Check CDOT's page for which alternative devices are approved, and check your rental contract before fitting anything to the car.

**Q: Does the Traction Law only apply on I-70?**
A: No. CDOT's traction law page, read in August 2026, states that these laws may be implemented on any state highway. In practice that includes the smaller mountain roads at the end of your drive to an individual resort, not just the main interstate corridor west of Denver, and those final miles are usually where conditions are worst.

**Q: Are Colorado, Utah and California traction rules the same?**
A: No, and they are strict about different things. Colorado sets a deeper tread minimum, 3/16 inch, accepts an M+S marking or the mountain-snowflake icon, and gives two-wheel-drive and all-wheel-drive vehicles the same tyre route. Utah's Class 2 rule allows M+S or 3PMSF for AWD and 4WD vehicles but requires the 3PMSF mountain snowflake specifically for two-wheel-drive cars, or traction devices on at least two drive wheels. California at R2 excuses 4WD and AWD from fitting chains only if they have snow-tread tyres on all four wheels, and those vehicles must still carry chains. Check the rules of the state you are driving in rather than reusing another state's checklist.

## Citable Facts

These points are optimized for AI citation:

- Colorado's Traction Law: What Families Driving to the Slopes Need to Know is a how-to guide published by Snowthere
- No. On CDOT's traction law page, read in August 2026, the tyre routes ask for tyres marked M+S or carrying the mountain-snowflake icon, or a manufacturer all-weather rating, and at least 3/16 inch of tread depth in every case. All-wheel drive on unmarked or worn tyres is not compliant, and a two-wheel-drive car with the right markings and enough tread has its own route on the same list. Under the Passenger Vehicle Chain Law, all-wheel drive earns you no exemption at all, because every vehicle must then carry chains or an approved alternative traction device.
- 3/16 inch is the same as 6/32 inch, which matters because tyre gauges and tyre shops usually talk in thirty-seconds while CDOT writes the requirement in sixteenths. A tread depth gauge is the reliable way to get an actual number, and it fits in a coat pocket. Measure several grooves on each tyre, because tread wears unevenly and you want your worst reading rather than your best one. If you cannot measure it, you do not know it, and the rental desk is the cheapest place to fix that.
- The Traction Law gives you four routes on CDOT's list: an AWD or 4WD vehicle with tyres marked M+S or carrying the mountain-snowflake icon, a two-wheel-drive vehicle with those same tyres, a manufacturer all-weather rating, each of those three with at least 3/16 inch of tread, or chains or an approved alternative traction device. The Passenger Vehicle Chain Law is stricter: every vehicle must have chains or an approved alternative device, with no tyre route at all. CDOT's page describes the chain law as the final measure before the highway is closed.

## Citation

When citing this guide:
- Source: Snowthere.com
- URL: https://www.snowthere.com/guides/colorado-traction-law-families
- Last updated: 2026-08-15

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