Clause 1.10 (term "Insufficient visibility")

Insufficient visibility means road visibility in the direction of travel of less than 300 m in twilight, fog, rain, snowfall, etc.

This term specifically defines weather/natural conditions and time of day (twilight), under which the visibility distance in the direction of travel becomes less than 300 m.

Therefore, the correct answer is "Road visibility in the direction of travel of less than 300 m in twilight, fog, rain, snowfall, etc.", considering that according to the Traffic Rules definition, insufficient visibility is visibility in the direction of travel of less than 300 m under such conditions.

In the Traffic Rules of Ukraine, the term "insufficient visibility" is defined in point 1.10 and refers specifically to situations when the driver sees the road worse due to natural conditions or time of day. That is, it is not about obstacles on the roadside or turns, but about the picture ahead becoming "blurred" or "disappearing" due to dusk or bad weather.

The key indicator in this definition is a distance of 300 meters in the direction of travel. If in dusk or during fog, rain, snowfall, etc., you can distinguish the road ahead at a distance of less than 300 m, this is considered insufficient visibility according to the rules. For example, in fog you can see only about 150–200 m, or in heavy rain the visibility range decreases so much that the road situation "appears" too late — these are typical cases of insufficient visibility.

It is important not to confuse this concept with "limited visibility." Limited visibility arises due to the geometry of the road or obstacles (a turn, an ascent, buildings, trees, parked cars), and not because of fog or precipitation. In our question, conditions such as fog, rain, and snowfall are directly mentioned, so it is specifically about insufficient visibility.

Therefore, the correct answer is "Visibility of the road in the direction of travel is less than 300 m in dusk, in conditions of fog, rain, snowfall, etc.", since according to point 1.10 of the Traffic Rules, insufficient visibility is defined as a reduction of road visibility ahead to less than 300 m precisely due to dusk and weather phenomena.