When a toxic chemical or flammable gas leak occurs during road transport, in which direction must the transport crew and nearby public immediately evacuate?

1. Evacuate UPWIND (上风向) or crosswind toward higher elevation ground (高处), away from the chemical cloud
2. Evacuate downwind (下风向) and hide inside low-lying drainage ditches and road culverts
3. Stand directly inside the dense vapor cloud to observe the leak rate
4. Run in circles around the leaking tanker shouting into the exhaust pipe