Under Article 58 of the Implementing Regulation, what must a driver do when a vehicle designated for transporting students is picking up or setting down students?

1. Stop completely in both directions and wait for the vehicle to withdraw a stop-sign arm and switch off its flashing red lights
2. Sound the horn to warn the students, then continue past at the normal speed limit
3. Overtake on the left immediately, before the students begin to move
4. Slow down, and stop if necessary, to let the vehicle make the movements needed for students to board or alight, without obstructing or disturbing them