5. Goreville, Illinois — 26.2 million people in range
Zeiler said the eclipse will reach its longest point in southern Illinois.
6. Salem, Oregon — 25 million people in range
"This is the first solar eclipse in a heavily populated United States," Zeiler added.
7. Sweetwater, Tennessee — 20.4 million people in range
"I think the wildcard is the impact of social media," he said. "A lot of people may feel inspired to get in a car and drive."
8. Festus, Missouri — 13.8 million people in range
"People should not casually expect to drive down on the morning of the eclipse," Zeiler said.
9. Lathrop, Missouri — 12.5 million people in range
Zeiler said his maps don't guarantee there will be terrible traffic in these drivesheds, but he considers the likelihood very high.
10. Greenville, South Carolina — 9.6 million people in range
Finding a place to go to the bathroom may also prove challenging, he added, though many cities plan to put out portable toilets.
11. Glendo, Wyoming — 8.6 million people in range
He also recommends bringing enough food, water, toilet paper, batteries, and other supplies to last you the journey, since small-town shops may be thinly-stocked under the crush of eclipse tourism.
12. Colombia, South Carolina — 5.5 million people in range
Zeiler said if you are driving to the path of totality, be sure to leave at least a day early on August 20, and plan to wait for traffic to clear for several hours after totality ends.
Zeiler's "drivesheds" maps show the routes that drivers are most likely to take.
Zeiler said he's given several presentations and seminars on these maps, including one to the American Association of State Highway and Transportation Officials, or AASHTO.