Four major roads will reverse their traffic lanes to help facilitate the mass exodus.
This isn't some guy on the internet sounding the alarm, this is our elected officials telling us that an incredibly risky hurricane is on its way, likely to the Carolinas.
In Charleston, South Carolina, people filled sandbags and stocked up on food.
Schools will be closed in Jasper, Beaufort, Colleton and Hampton counties starting Tuesday. Eastbound lanes of Interstate 26 heading into Charleston and US 501 heading into Myrtle Beach will be reversed when the order takes effect. The state's emergency management division has posted additional information on the evacuations and how to prepare.
Hurricane Florence is intensifying and expected to transform into a major hurricane as it barrels toward the southeastern USA coast, where forecasters expect a life-threatening storm surge, major flooding and damaging winds this week.
One of the factors making this storm so risky is the likelihood that the storm will slow down considerably as it makes landfall.
SC governor Henry McMaster also suspended his campaign and asked President Donald Trump for a federal emergency declaration. "We have already began mobilizing our assets to respond accordingly, and we are here for you!"
Tropical storm winds are forecast to hit the region sometime Thursday morning, with landfall occurring late Thursday night.
I say "active" hurricanes because there are more storms out there that could mature into a hurricane. But the track still places the storm over central North Carolina Friday as a weak category 1 hurricane or a strong tropical storm.
Gov. Rick Scott released a statement on Monday urging Floridians to be prepared for the unexpected and remain on alert about Hurricane Florence.
But Florence stands out from the other hurricanes.
Hurricane Helene, was spinning in the Atlantic off West Africa's Cape Verde islands with 85-mph (140-kph) winds on Monday, but did not appear to pose an immediate threat to land.
The governor of neighbouring North Carolina also ordered an evacuation of the Outer Banks, barrier islands that are a popular tourist destination, and parts of coastal Dare County, while a state of emergency was declared in Virginia.
The United States was hit with a series of high-powered hurricanes a year ago, including Hurricane Maria, which killed about 3,000 people in Puerto Rico, and Hurricane Harvey, which killed 68 and caused an estimated US$1.25 billion in damage from catastrophic flooding in Houston.