Everything You Need to Know About the Mountain Law (Loi Montagne)

Last updated on December 15, 2025

Since winter 2021, the Mountain Law (Loi Montagne) has gradually become part of everyday life for French motorists ^{by making it mandatory to equip vehicles with winter tires or to carry snow chains or snow socks from November 1, 2025, to March 31, 2026}.

This article explains everything you need to know about the Mountain Law, helps you determine whether you are affected, and shows you how to stay compliant before hitting the road.

Too long? Here are the key points!

• The Mountain Law applies every year from November 1 to March 31 in 34 French departments.
• In these areas, you must be equipped with 3PMSF-certified winter tires or carry snow chains or snow socks in your vehicle.
• Since winter 2024–2025, M+S tires alone are no longer recognized as winter equipment.
• Discover our map of the affected departments below.
• The affected zones are indicated by specific road signs and defined by prefectural decrees.
• Failure to comply may result in a €135 fine and vehicle immobilization.
• Proper equipment improves traction, braking, and overall safety on snowy or icy roads.

What Is the Mountain Law?

From November 1 to March 31 each year, the Mountain Law requires drivers who live in or travel through one of the 34 French departments with mountainous areas to equip their vehicles with specific winter equipment. If a motorist drives through a designated zone without the required equipment, they risk a €135 fine, possible vehicle immobilization, and—most importantly—put their own life and the lives of others at risk.

As you may have guessed, the purpose of this law is not to inconvenience drivers, but to protect them from winter weather conditions, including freezing temperatures, ice, and snow.

Which Areas Are Affected?

The Mountain Law aims to ensure road safety in the following mountain ranges:
The Alps, the Massif Central, Corsica, the Pyrenees, the Jura Mountains, and the Vosges Mountains.

The various prefectural decrees applicable in the concerned departments are available on the French Road Safety website.

You can also find the list of municipalities where winter equipment is mandatory.

Which Equipment Is Mandatory Under the Mountain Law in 2025?

Winter Tires

To drive freely in the 34 concerned departments, you must have at least one of the following: all-season tires, winter tires, snow chains or snow socks

Winter tires and some all-season tires are marked with the 3PMSF symbol:

• 3PMSF stands for “Three Peak Mountain Snowflake.” This marking appears on the sidewall of winter tires and most all-season tires. It corresponds to a certified standard, issued by a laboratory and regulated by the European Union.
  The 3PMSF marking guarantees good grip on roads affected by winter conditions such as cold, ice, and snow.

Important: Since November 1, 2024, ^{M+S tires are no longer authorized under the Mountain Law}.
Drivers must now be equipped with 3PMSF-certified tires. All 3PMSF tires are M+S, but not all M+S tires are 3PMSF.

Snow Chains or Snow Socks

If your vehicle is not equipped with 3PMSF winter tires, you must carry in your trunk:

• Snow chains
• Or snow socks

These devices must be able to equip at least two drive wheels and must be immediately usable in the event of a roadside check or difficult driving conditions.

Which Vehicles Are Covered by the Mountain Law?

The regulation applies to:

• Passenger cars
• Commercial vehicles
• Vans
• Motorhomes
• Heavy goods vehicles
• Coaches and buses

Requirements may vary slightly depending on the vehicle type, but the principle remains the same: ensuring sufficient traction in winter conditions.

How Can You Recognize a Mountain Law Zone?

Specific road signs have been introduced to indicate entry into and exit from areas where the Mountain Law applies. These are as follows:

Once you see this signage, your vehicle must be equipped with approved winter equipment.

What Are the Penalties for Non-Compliance?

If you are stopped in a regulated zone and your vehicle does not comply with Mountain Law requirements, you may face:

• A €135 fixed fine
• Vehicle immobilization if conditions require it

While enforcement initially focused on education, checks are now fully enforced, and the regulation is entirely applicable.

Good Practices Before Heading to the Mountains

• Check tire pressure
• Test snow chains or snow socks in advance
• Check brake condition
• Check the battery
• Check fluid levels (coolant, brake fluid, engine oil, windshield washer fluid)
• Use winter windshield washer fluid rated down to –20°C, which helps remove frost and winter residues
• Keep a de-icing spray and ice scraper in your trunk

Conclusion

The Mountain Law is not an unnecessary constraint, but an essential safety measure for driving in mountainous areas during winter. In 2025, the rules are clear, well known, and fully enforceable.

Before setting off this winter, take a few minutes to ensure that your vehicle fully complies with the regulations.