The sign you mentioned, "Motor vehicles with a permissible total weight over 3.5 t without arrow symbol," indicates a restriction for vehicles. This sign prohibits motor vehicles that have a permissible total weight exceeding 3.5 tons from entering or using the specified road or area.

This regulation is typically in place to minimize wear and tear on roads, manage traffic in urban areas, or enhance safety by reducing the presence of large and heavy vehicles in certain locations. Drivers of vehicles over this weight limit must find alternative routes or designated roads that allow such vehicles.

If you have any other questions about traffic rules or need further explanations, feel free to ask!