What must you remember when you see this traffic sign?

This traffic sign indicates that snow chains must be used on the vehicle's tires. It is a mandatory sign usually placed in areas where snowy or icy road conditions are common, ensuring better traction and safety.

Additionally, when this sign is present, there is often a maximum permissible speed limit, which in this case is 50 km/h. This speed limit is set to ensure safe driving conditions while using snow chains, as higher speeds can be dangerous or cause damage to the chains and tires.

The third option, "Track-vehicles have priority," is not related to this sign and is therefore incorrect.

In summary, this sign requires drivers to use snow chains and restricts the maximum speed to 50 km/h for safety in winter conditions.