CDL Vehicle Combination Practice Test

What is the appropriate action when coupling the trailer?

1. Back up quickly until the tractor hits the trailer

2. Back up slowly until the fifth wheel touches the trailer

3. Use manual force to bring the two units together

4. Leave a gap and adjust after coupling

The correct answer is: Back up slowly until the fifth wheel touches the trailer

When coupling a trailer to a tractor, backing up slowly until the fifth wheel touches the trailer is the recommended action. This approach allows the driver to maintain control and alignment as the tractor approaches the trailer, ensuring that both units are properly positioned for a secure connection. Moving slowly gives the driver the opportunity to make necessary adjustments if alignment is off, reducing the risk of damage to either unit during the coupling process. This careful approach also helps in avoiding potentially hazardous situations that may occur when backing up too quickly, as high-speed movements can lead to improper coupling or even accidents if the tractor collides with the trailer. Additionally, relying on manual force to bring the two units together is not ideal because it can create misalignments or cause damage, while leaving a gap and then trying to adjust after coupling may lead to difficulties in achieving a secure fit. Thus, the correct practice emphasizes patience and precision while backing up to ensure a safe and efficient coupling process.