When driving into a highway tunnel, what essential lighting and operational precautions must the driver take?

1. Turn on high beams to maximize distance vision and accelerate to pass through quickly
2. Turn on low-beam headlights before entering, remove sunglasses, maintain increased following distance, and refrain from overtaking, changing lanes, or stopping inside the tunnel
3. Honk the horn continuously and turn on hazard warning flashers throughout the tunnel
4. Switch off all lights to adjust eyes to interior tunnel lighting