What would you do if city authorities ordered you to evacuate ?

There are only two choices - comply or refuse, and neither is going to be much fun. For many it means loading up the car with their family, pets and anything else that fits, then joining heavy traffic to shuffle towards an uncertain future. While the upheaval is inconvenient at best, choosing to stay could be the biggest gamble of your life.

Some types of disasters allow for warnings and time to evacuate. Bushfires frequently reach the edges of the suburban sprawl, initiating rushed evacuations, sometimes with only minutes to spare. In the case of hurricanes, sophisticated weather analysis and satellite images can give those in danger up to 3 days warning.

In the case of Hurricane Katrina in August 2005, the city government of New Orleans issued a mandatory evacuation of the entire city two days before disaster struck. While there were a large number of people who did not have the means to leave, others remained in the city by choice to face the fury of nature.

One factor in this seemingly crazy decision was the regularity of hurricane warnings over the years. Most hurricanes had amounted to nothing worse than a heavy downpour, so many residents calculated the inconvenience of leaving against the amount of actual danger they would face, and figured there was no good reason to walk away, not when so many storms billed as the Big One had ended up heavy rain and hot air. People have jobs, people have commitments, organising to uproot your life at short notice would surely test the preparedness of anyone. And of course, many folk would simply have no money, no transport and no contacts out of town.

A tourist performed her own calculations shortly before the city was ruined - "They say it's mandatory evacuations except for the hospitals and hotels. So it can't be that bad."

Tourists who couldn't organise transport out of the city did what they called vertical evacuation - getting rooms high enough in buildings that were known to have survived earlier major storms.

Despite the huge inconvenience of evacuating, it should be remembered that authorities do not like to shut down their cities unless there is a compelling reason. Almost everyone who stayed to face Hurricane Katrina regretted their decision.