What must a commercial truck driver do if their vehicle breaks down and becomes completely immobilised on the active carriageway of a national highway at night?

1. Switch on the hazard warning signal, keep the position and marker lights lit, place the pre-signalling triangles at least 30 metres from the vehicle, and get clear of the carriageway
2. Switch off all lights to save battery power and sleep in the cab until morning
3. Leave the vehicle unlit on the carriageway and walk to the nearest town for help
4. Rely on the hazard warning signal alone; triangles are only required in daylight