Which vehicles are not allowed to overtake here?

The sign indicates that overtaking is prohibited for specific vehicles. In this case, trucks and truck-tractor combinations are not allowed to overtake due to safety concerns, traffic flow, and the larger size of these vehicles, which can make overtaking more dangerous.

The regulation aims to prevent accidents and ensure smoother traffic flow, particularly on narrower roads or in areas with higher traffic density. Cars are not included in this prohibition, allowing them to overtake where safe.

In summary, the rules are designed to manage risks associated with larger vehicles, maintaining safety for all road users.