In the outback, a flat can be life threatening. Most people that live out there carry three things- 5 gallons of water, 5 gallons of spare gas, and at LEAST 2 spare tires. They carry as many tires as possible.
There was an episode I saw last year of "I shouldnt be alive" (or as me and my wife call it- "Im a real lucky *******") A father took his young daughter on a day fishing trip, and had three flats on his range rover before he ran out of spares...by the 4th flat, he was stuck cuz he lost traction with the flat tire. They take flats quite seriously there.