What action should a driver take when experiencing a failure in the trailer service line?

When a driver experiences a failure in the trailer service line, stopping in stages is the correct action to take. This approach allows for a controlled response to a potentially dangerous situation. A gradual reduction in speed helps maintain stability and control over the vehicle, especially given that sudden braking or stopping could lead to the truck losing balance or the trailer swaying or fishtailing.

In contrast, stopping immediately could lead to the vehicle being halted abruptly, which can be hazardous, particularly on a busy road or if there is limited space. Increasing speed gradually would be counterproductive, as it could further increase the risk of losing control. Continuing to drive cautiously without addressing the service line issue could result in a more severe failure, increasing the risk of accidents or equipment damage. Thus, stopping in stages is the safest and most effective response to a failure in the trailer service line.