Parents or guardians are responsible for the safety, conduct, and the timely arrival of their children to, from, and at the designated school bus stop before the arrival of the school bus for pick up and transport to school and the timely departure of the children after the school bus leaves the designated school bus stop after transporting the children from school. For purposes of this section, the phrase "arrival of the school bus" includes the time that the school bus assigned to the school bus stop activates the required pedestrian safety devices, stops, and loads or unloads students until the school bus deactivates all pedestrian safety devices.