Clause 30.3 (subclause "l" — identification mark "Studded Tires")

The following identification marks are installed on the respective vehicles: p) "Studded Tires" — an equilateral white triangle with the vertex upwards and a red border, inside which the black letter "Ш" is inscribed (the side of the triangle is at least 200 mm, the width of the border is 1/10 of the side). The mark is placed at the rear of vehicles equipped with studded tires.

This clause directly defines the purpose of the "Studded Tires" identification mark and the condition for its use: it is installed (placed at the rear) precisely when studded tires are installed on the vehicle.

Therefore, the correct answer is "Studded tires are installed," given that according to the definition of the Traffic Rules, the "Studded Tires" identification mark is placed at the rear of vehicles equipped with studded tires.

This question concerns the identification sign "Studded Tires." It is not placed "for decoration," but so that other road users immediately understand: the vehicle is equipped with studded tires, and therefore its behavior on the road may differ from the usual.

The answer is directly indicated in clause 30.3 (p) of the Traffic Rules of Ukraine: this sign is used specifically on vehicles equipped with studded tires, and it is placed at the rear of the vehicle. That is, the purpose of the sign is clearly linked not to the type of vehicle, not to the cargo, and not to weather conditions, but to a specific feature of the wheels.

The practical meaning of such a designation is simple. First, studded tires in winter conditions often provide different braking; in particular, on slippery surfaces, the vehicle may stop differently than a vehicle ahead with non-studded tires. Second, during movement, studs can fly out of the tread and pose a risk to vehicles behind, so the sign serves as a warning and a reason to maintain a greater distance.

Therefore, the correct answer is "Studded tires are installed," because according to clause 30.3 (p) of the Traffic Rules, the identification sign "Studded Tires" is installed on vehicles that have studded tires, and it informs other drivers of this feature.