Some dare not by fear

From my son's (French) school, an emailed note about late arrivals:

Subject: Delay college students

Colleagues,

We noticed that some college students (especially 6) do not dare knock on the grid when they are late in the morning. Therefore, they remain outside / roundabout or return home until the next hour. Some dare not by fear, others by shyness.

This is not safe for our students. I would appreciate to encourage them to enter the gate / lodge and the service person will leave school to enter. They will then be directed to their school lives.

Note: This note does not apply to delays students.

Thank you for your cooperate