During heavy torrential rainfall when windshield wipers set at maximum speed cannot clear water fast enough to provide adequate forward vision, what is the safest driving response?

1. Stick your head out of the side window to see ahead while continuing at 80 km/h
2. Turn on low beams, clearance lamps, and hazard flashers, decelerate gradually, guide the vehicle safely off the carriageway into a service area or nearest exit, or pull fully onto the emergency shoulder and await storm abatement
3. Accelerate to generate wind shear that blows rain off the windshield
4. Turn off headlights to reduce glare on the inside of the glass