What is the primary action involved in rearward relief?

The primary action involved in rearward relief pertains to the concept of managing traffic flow to ensure the safety and efficiency of emergency response efforts. In the context of rearward relief, it specifically involves the highway patrol taking the initiative to turn traffic around. This is crucial in situations where the ambulance or other emergency vehicles need to navigate through congested or blocked areas quickly.

By redirecting vehicles, the highway patrol helps to create a clear path for ambulances to reach their destination or to facilitate the safe evacuation of individuals from hazardous situations. This action is vital because it not only enhances the response time of emergency services but also minimizes the risks associated with traffic congestion during critical moments.

The other choices, while related to traffic management, do not encapsulate the essence of rearward relief as effectively as the action of actively turning traffic around. Other duties—like stopping traffic for safety assessments or directing traffic off main roads—are important but focus more on traffic control rather than the rapid and necessary redirection needed in emergency scenarios.