Why should chocks be used when parking a trailer without spring brakes?

Using chocks when parking a trailer that does not have spring brakes is essential for safety, as they help prevent the trailer from rolling. If there is a loss of air pressure in the braking system, such as through a leak, the emergency brake system could disengage. Without adequate braking mechanisms, the trailer could move unexpectedly due to gravity or other forces. Chocks serve as a physical barrier that keeps the trailer stationary, ensuring that it does not roll away, thus significantly enhancing the safety of the parking situation.

While other options might seem plausible in different contexts, they do not directly address the critical safety concern presented by a trailer lacking spring brakes. For example, fuel efficiency and load securing are important aspects of trailer management, but they are not relevant to the immediate danger of the trailer rolling when parked. Similarly, coupling the trailer is a separate task that doesn’t relate to the need for chocks when the trailer is stationary.