Bay Area Rapid Transit (BART) Practice Exam 2026 - Free BART Practice Questions and Study Guide

The aspect of train design that may include features for retractable couplers is coupling mechanisms. Coupling mechanisms are specifically designed to connect individual train cars to each other while enabling smooth movement and adjustments as needed. Retractable couplers are innovative elements within this category, allowing for easier coupling and uncoupling of cars, improving operational efficiency.

In contrast, braking systems focus on the ability of the train to come to a halt, emphasizing safety and stopping power rather than connections between cars. Structural integrity pertains to the overall strength and stability of the train's design, ensuring it can withstand various forces during operation; this area does not directly involve couplings. Lastly, passenger accommodations relate to the comfort and amenities provided for the passengers, which is not connected to the technical aspects of how train cars are joined or coupled together.