(CNN) — Florida Gov. Rick Scott says to expect more evacuations across the state ahead of Hurricane Irma, the powerful Category 5 storm plowing through the Caribbean.
“If you’re told to evacuate, get out quickly,” Scott said Wednesday. “We can expect additional evacuations as this storm continues to come near our state.”
Based on Irma’s projected path, which includes Florida’s heavily populated eastern coast, the enormous storm could create one of the largest mass evacuations in US history, CNN senior meteorologist Dave Hennen said. The greater Miami area alone has about 6 million people.
Monroe County, home to the Florida Keys, has already ordered mandatory evacuations. Broward County, which includes Fort Lauderdale, issued a mandatory evacuation Wednesday for areas east of Federal Highway.
Other eastern Florida population centers could also see similar evacuations soon, depending on the path of the hurricane, which is expected to near Miami on Sunday.
But an evacuation of that scale could lead to miles-long gridlock, as happened with attempted mass evacuations during Hurricane Floyd in 1999 and Hurricane Rita in 2005. When Hurricane Harvey began threatening southeast Texas about two weeks ago, Houston officials decided not to issue voluntary or mandatory evacuations, partly because of memories of those problems.
Gov. Scott said he was aware of the potential for extensive gridlock and advised residents who are told to evacuate to do so immediately.
“Evacuation orders are going to be given in a timely manner so people have time to evacuate,” Scott said. “But if you wait, that’s when the problems are going to happen.”
Limited evacuation routes
One issue with a mass evacuation is that Florida relies on two primary highways that go north and south: I-95 along the east coast and I-75 further west. Those highways, as well as the Florida Turnpike, US-27 and other smaller roads that run north, will be “tremendously” clogged if the storm hits, Senator Bill Nelson of Florida said.
“If this monster comes right up the peninsula of Florida, you’re gonna have a mass out-migration from the south to the north, and it’s gonna clog the roads something tremendously,” Nelson said. “Therefore, if you are going to evacuate, once the evacuation order is given, don’t wait around.”
Sen. Marco Rubio of Florida said that evacuations in Monroe County and parts of Miami Beach were already putting strain on highways headed north.
Indeed, Florida Department of Transportation cameras already showed heavy traffic on I-75 near Tampa midday Wednesday.
Nowhere to hide
As Harvey bore down on Texas, residents there could flee north, east or west to escape the storm. In South Florida, however, they can only go north.
Hurricane Irma’s cone of potential landfall currently includes the entire state of Florida, meaning that residents may not be able to flee to the state’s Gulf coast to avoid its wrath.
Florida is relatively narrow. Fort Lauderdale on the east coast and Naples on the west coast are separated by just over 100 miles. Even in the central part of the state, only 130 miles separate Clearwater on the west coast from Melbourne on the east coast.
For comparison, tropical storm-force winds from Irma cover over 65,000 square miles — an area larger than the entire state.
“A storm of this size can have effects statewide, and everyone must be prepared,” Gov. Scott said.
Hurricane Floyd’s traffic jam
Major evacuations have created significant problems in the past when millions of residents took the roads at the same time.
Florida saw this in 1999 during Hurricane Floyd. The storm was headed toward Jacksonville, in the northeast corner of the state, and officials there ordered evacuations. The storm ultimately turned further north and made landfall in North Carolina.
In all, about 3 million people across Florida, Georgia, South Carolina and North Carolina attempted to evacuate, making it the largest evacuation effort in US history, according to a FEMA press release from 2000.
Many of those evacuees became stuck in gridlock in what FEMA charitably described as a “frustrating effort.”
“They sought only to flee the hurricane’s landfall. Instead, they created the largest, longest, and most incredibly snarled traffic jam ever known,” FEMA wrote.
Sen. Nelson said that one lesson from that storm is that Florida officials should make entire interstates one-way to better accommodate the flood of evacuees.
“Back then they did not, and that’s why people were stuck in traffic,” he said. “They actually had to turn around and go back home because there was no egress out of the city.”
Mindful of past problems with mass evacuations, Houston officials last month told residents to hunker down in their homes until Hurricane Harvey passed. As the city flooded and residents became trapped in their waterlogged homes, Houston mayor Sylvester Turner defended his decision not to evacuate.
The alternative, he said, could have been worse.
“You literally cannot put 6.5 million people on the road,” Turner said last week. “If you think the situation right now is bad, you give an order to evacuate, you are creating a nightmare.”
Houston experienced that firsthand during Hurricane Rita in 2005, when officials issued mass evacuation orders.
During that evacuation, a bus carrying elderly evacuees caught fire and exploded, killing at least 24 people and jamming a major evacuation route. Others died during the evacuation due to heat exhaustion, according to the National Hurricane Center.
“You issue an evacuation order and put everyone on the highway,” Turner added, “you are really asking for a major calamity.”
Airlines adding flights
For Floridians who don’t want to risk chaos on the highways, a flight out is another option.
Delta Air Lines said it has added flights out of Miami, Fort Lauderdale and Key West to Atlanta, its largest hub. The airline also is allowing passengers affected by Irma to rebook flights without paying a fee.
American Airlines and United Airlines also said they are waiving change fees for passengers whose travel plans are impacted by Irma.
However, American Airlines said it will wind down operations Friday afternoon at its Miami hub as well as other south Florida cities. Operations will be canceled throughout the weekend, the airline said.