“If everybody decided to evacuate, it would probably be worse than what happened in Houston, because we only have two major north-south highways,” said Renne, director of FAU’s Center for Urban and Environmental Solutions. “There’s no way everybody can evacuate.”
The good news is that unlike Houston, evacuations plans in South Florida don’t call for entire cities to clear out. Only those people in flood zones — 300,000 residents in Palm Beach County, according to officials — face mandatory evacuations. Counties also coordinate so that calls for evacuations are spaced out enough that mandatory evacuees aren’t running into other mandatory evacuees north of them.
But with a monster storm like Hurricane Irma certain to harm anything in its path, many South Floridians who do not live in evacuation zones have either left the area or are seriously thinking about it.
Bill Johnson, director of the Emergency Operations Center in Palm Beach County, said that’s not a great idea.
"Seven million people live south of Jupiter, and north of Jupiter the two major thoroughfares drop down to two lanes, so we cannot move all these people," Johnson said, referring to I-95 and Florida's Turnpike. "Evacuate in miles, not hundreds of miles. We are encouraging everyone to stay within the county."
Even if all 300,000 Palm Beach County residents in evacuation zones chose to leave town, it might not make a noticeable difference on the roadways. Johnson points out the county handles twice that number of motorists twice a day during rush hour.
The bigger concern are the hundreds of thousands who voluntarily decide to leave, crowding highways being used by those forced to abandon their homes.
“The thinking from people is that they can outrun a hurricane, and that’s the farthest thing from the truth,” Johnson said. “They’re just running from the wind. Wind is not the killer.”
Johnson points out the vast majority of those killed last month in the aftermath of Hurricane Harvey died in flooding. If you don’t live in a flood-prone area, Johnson advises, it’s best to hunker down at home or go to a nearby shelter.
And as Hurricane Irma creeps closer to Florida, it may already be getting a little late to leave, especially for those who have no specific destination to wait out Irma.
“When a major storm is bearing down on you, people will definitely panic,” Renne said. “But it’s better to panic early than panic late.”
Visitors to the Florida Keys were told to leave Wednesday morning and its 70,000 residents must go Wednesday night, Gov. Rick Scott said.
Evacuation orders could be issued Thursday in coastal Miami-Dade County, and parts of Broward County have already begun evacuations.
A new evacuation plan rolled out this year by the Florida Department of Transportation can permit motorists to drive on the shoulders of highways with two lanes in each direction, including Interstate 75 along Alligator Alley. The turnpike can be turned into a one-way roadway beginning just north of the Boynton Beach interchange and ending in Orlando in the event of a Category 3 hurricane (111 mph) or stronger, officials said.
“One of the things about evacuations that’s important for people to understand is that they’re not made to be a convenience, but to save lives,” said Brian Woshon, a professor of civil engineering at LSU who studies evacuations. “It’s not going to be comfortable and not everybody is going to be happy when you’re trying to move hundreds of thousands, if not, millions of people.”
– Palm Beach Post staff writer Joe Capozzi contributed to this story.