What should you do if an ambulance comes up behind you flashing red lights or sounding its siren?

In New Zealand, the correct response when encountering emergency service vehicles, such as ambulances, reflects respect for and support of the efficiency and safety of emergency service personnel. When an ambulance is flashing its red lights or sounding its siren, it indicates that the ambulance is responding to an emergency and may be saving a life. At this time, it is the responsibility of other road users to ensure they do not obstruct the ambulance's quick passage.

Option 4, which involves slowing down and moving to the left side of the road, and stopping if necessary, is the correct action. This allows the ambulance to have a clear path to reach its destination as quickly as possible to complete its rescue mission. This behavior not only complies with New Zealand traffic regulations but also demonstrates respect and understanding for emergency service personnel and those in need of assistance.