A vehicle should not pass another vehicle on a grade unless the maneuver can be completed in less than?

A vehicle should not pass another vehicle on a grade unless the maneuver can be completed in less than one-half mile. This is important for safety, as visibility and road conditions can be limited on inclines, making it harder to judge the distance and speed of oncoming traffic. Drivers should prioritize caution and ensure they have ample space to complete the pass safely.