Rule 7:
Stop driving-immediately.

When the city of Nagasaki was flooded in 1982, some 20,000 vehicles were damaged; 20 drivers died as their vehicles were dragged underwater or buried by landslides.
In 2004 during Typhoon 16, vehicles were inundated or blown into rivers in various locations, causing several deaths.
It is extremely dangerous to drive during a major storm. Brakes will not work when tires are half underwater, and the vehicle may be swept away when the water level is 10 to 20 centimeters, or 4 to 8 inches, above the bottom of the doors.

If you are driving, move immediately to higher flat land, park your vehicle and leave it until the storm is over. Wherever your car is parked, move it out of the roadway if possible. Leave the key in the ignition so it can easily be moved out of the path of emergency vehicles during relief operations.