What is the primary function of retractable couplers?

Retractable couplers are specifically designed to facilitate the easy separation of train cars. This function is particularly important in operations where trains need to be split or reconfigured, often for maintenance or when changing train configurations such as adding or removing cars from a train set.

With retractable couplers, the mechanism allows for a smooth and efficient release of the connection between train cars without requiring excessive manual effort, thereby increasing operational efficiency. This feature significantly reduces the risk of damage to the train components during the uncoupling process and promotes quicker turnaround times for trains, which is essential in busy transit systems like BART.

While connecting multiple train cars is a fundamental function of any coupler, retractable couplers specifically enhance the ease of separation, making option three the most accurate representation of their primary purpose.