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What has been dubbed the U.S. eclipse of the century could draw as many as 7 million people to the areas in which the sun will be 100% blocked out. The region runs from Oregon diagonally across the country to South Carolina.

GreatAmericanEclipse.com reports that 12.25 million people already live in the area where the sun will be completely blotted out by the moon. This area is about 65 miles wide. Based on the location of the path, a huge number of Americans could travel to the area to watch the event on August 21. The organization’s experts report:

The path of totality cuts a diagonal path across the nation from Oregon to South Carolina and most Americans live within a day’s drive to the path of totality.

The United States has an excellent highway system and most American families have it within their means to take a short driving vacation.

August is an ideal month for a vacation; the weather is warm and the chance of summer storms has diminished in much of the nation.

Most schools have not yet begun their fall session by August 21st and some schools near the path of totality are scheduling a late start.

Social media will have a huge impact on motivating eclipse visitors. The eclipse is exactly the type of event guaranteed to go viral on Twitter, Facebook, Instagram, and other social platforms. We expect that many people will only make plans to go in the week before eclipse day.

Take a vacation, see the eclipse.

The organization did some very rough math about how many people would actually travel to witness the event, and the range of their estimate is very broad:

A person who is 200 miles away from the centerline of eclipse will have certainly heard about the eclipse within the week before from TV or social media. This average person will receive the impression that the total solar eclipse is something very special to see.

Not every one has the freedom to travel. Monday is a work day and for some, a school day. Some may also be deterred by myths about viewing the eclipse or scary stories of traffic congestion.

Despite the many news stories about the spectacle of the eclipse, some people will be completely disinterested in the eclipse.

Based on this profile of an average person living 200 miles away, I estimate that this population has a high probability of 2% to drive into the path of totality and a low probability of 0.5%.

I halve these estimates for people living 400 miles away. I further halve these estimates for people living 800 miles away.

I apply this formula to every populated area in the United States using ArcGIS software by Esri.
The sum estimate from this analysis is that between 1.85 and 7.4 million people will visit the path of totality on eclipse day.

The “school day” part is s real hindrance to people who want to see a once-in-a-lifetime event.