Minimum speedUkraine
1. Minimum speed
A minimum speed is the lowest speed that vehicles are required to maintain on a particular road or under specified conditions. Minimum-speed rules are intended to prevent vehicles travelling unnecessarily slowly from disrupting traffic or creating large speed differences between road users.
A minimum speed does not require drivers to maintain that speed when traffic, weather, visibility, road conditions or safety require them to slow down. The way minimum speeds are indicated and enforced varies between countries.
Does the 40 km/h motorway access threshold in Ukraine mean I must always drive that fast?
Except at specially equipped places, motorway rules exclude mechanical motor vehicles whose design or condition prevents them from reaching 40 km/h. This is a vehicle admission condition, not an instruction to maintain that speed in congestion or unsafe conditions. Separate speed restrictions and safe-driving duties still apply.

Traffic rules
Ukraine