Gridlocks are expected across the U.S. for several days before and after the eclipse.

“It is similar to what would happen for an evacuation for a hurricane,” said Howard Duvall, councilman for Columbia, South Carolina.

To help the public grasp the size of these traffic jams, Duvall said it’s easier, and less frightening to compare the impact to a football game, even if no football game aside from the Super Bowl can really get close to the scale of traffic. “This is going to be like having 10 Carolina-Clemson football games on the same day,” Duvall said.

Joleen Kelley, spokeswoman for Marion County, Oregon, said the more dispersed traffic will require officials to reroute travels away from small two-lane roads.

“A lot of times when there is a big event, [traffic is] usually central to an area, and this time with the eclipse it will cover the state,” she said. “It will go border to border in Oregon.”

All that traffic is likely to trap EMS, fire, and police in its grasps. Larsen said the city plans to position emergency responders across the city ahead of traffic, for example on both sides of a critical bridge.

Some jurisdictions are pulling in additional personnel from other counties and states.

Regular deliveries might also get stuck in transit, so grocery stores, gas stations and even hospitals have to think about supply chain concerns in the weeks before eclipse travelers get on the road.

Hospitals have begun ordering extra medicine for their patients for that week, plus some supplies to treat an influx of minor injuries that go hand-in-hand with large crowds, like heat stroke.

Gas stations have been warned to keep up with supply that week, Kelley said. “We certainly don’t want a run on gas,” she said.