After a certain amount of time on an approved pass, the student's pass expires, and they are alerted to scan back into class.

Until they scan in, the time out of class will continue count against their efficiency score, but the next student in line will automatically be able to use the pass if an active pass expires.

This feature is designed to create a sense of urgency for students so passes are available for their classmates. Additionally, it prevents students that abuse passes from holding up the line for the rest of the students.