In which situation may legal maximum weights not be safe?

Legal maximum weights may not be safe in bad weather or mountainous areas due to the additional risks associated with these conditions. In bad weather, such as rain, snow, or ice, road traction can be significantly reduced, increasing the likelihood of losing control of the vehicle while carrying maximum legal loads. These conditions can lead to longer stopping distances and reduced maneuverability, making it dangerous to operate at maximum capacity.

In mountainous areas, the challenges increase further. Steep grades can cause heavy vehicles to struggle with acceleration and braking. A fully loaded truck going downhill may experience brake overheating due to the added weight and the necessity of maintaining control on declines. Conversely, ascending steep inclines with maximum legal weights can strain engines and drivetrain components, complicating safe operation.

All these factors combined make it clear that adhering strictly to legal weight limits in such conditions may compromise safety, even though the weights may be permissible under normal circumstances.