How often should drivers stop to check their cargo during a trip?

The correct answer is based on regulations that recommend drivers check their cargo after the initial 50 miles of travel and then at intervals of every 150 miles thereafter. This practice is important for ensuring that the cargo remains secure throughout the trip, as loads can shift during transportation due to road conditions, turns, and braking. By checking the cargo at these specified intervals, drivers can prevent potential safety hazards such as shifting loads that could affect vehicle handling or cause spills, which might endanger other road users.

In contrast, the other options suggest check intervals that are either too frequent or insufficient. For instance, stopping after every 25 miles could lead to excessive delays in transit without a significant increase in safety, while checking only at rest stops may not provide adequate oversight of the load's condition during extended driving periods. Lastly, checking every hour of driving may not align with recommended practices, which focus more on specific mileage intervals rather than strict time frames. Therefore, the mileage-based approach of the correct choice balances safety with efficiency for drivers on the road.