In what situation might legal maximum weights be unsafe?

When considering the safety of legal maximum weights, driving in mountains or bad weather presents unique challenges that can make these weights unsafe. On steep inclines, heavy loads can put excessive strain on a vehicle's braking system, making it harder to slow down or stop, especially on downhill grades. Bad weather conditions, such as rain, snow, or ice, can further reduce traction and increase the risk of losing control with a heavy load. The combination of steep terrain with adverse weather conditions creates scenarios where the safety margin is significantly reduced, making it crucial for drivers to adjust their loads and speed accordingly to maintain control and ensure safety on the road.

In contrast, driving during clear weather on cleared highways generally provides safer conditions for handling maximum weights, as visibility and traction are typically optimal. Being below speed limits does not inherently compromise safety unless other factors, such as road conditions or vehicle handling, come into play.