What is the requirement for the engine of an ADR vehicle during loading and unloading operations?

1. The engine must be kept running to power the hazard warning lights
2. The engine must be shut off, except where its power is required to operate pumps or other loading/unloading machinery
3. The engine must be run at high revs to prevent fuel line freezing
4. The engine must be started and stopped every 5 minutes to test the starter motor