What does the term "door travel" refer to in elevator service?

The term "door travel" specifically refers to the distance the door moves when it opens and closes. This measurement is crucial in elevator installations because it determines how effectively the door can perform its function of providing access to the elevator cab while ensuring safety and operational efficiency.

Understanding the distance of door travel is essential for properly aligning the doors with the elevator shaft and ensuring they do not obstruct passage or fail to meet safety standards. The design and operation of the door system depend heavily on this distance, as improper travel can lead to safety hazards, inefficient operation, or mechanical failure.

In contrast, the other options focus on different aspects of door operation, such as speed, completion time, and weight, which, while relevant, do not define "door travel" itself. These factors are separate considerations that influence the overall door performance but do not specifically relate to the distance moved during the opening and closing actions.