COLUMBIA, S.C. — “Don’t look at the sun while driving.”

That may seem like common sense advice, but as the Aug. 21 solar eclipse approaches, South Carolina public safety officials worry the event will be so extraordinary that people may forget even the most basic safety rules.

“It’s going to be a great temptation to look up because it is so historic,” South Carolina Adjutant General Robert Livingston said at a news conference Thursday.

South Carolina will see a total eclipse in a 70-mile (110-kilometer) strip across its three major cities starting around 2:40 p.m. on Aug. 21. It is the last place in the U.S. to see the event, which will sweep across 14 states, beginning in Oregon.

The biggest worry for emergency planners is traffic as an estimated 1 million visitors strain the road network. They fear many may choose to just stop on the shoulder or in the middle of major highways as the sun disappears behind the moon.

The Highway Patrol said it plans to have all available troopers working to make sure roads remain as clear as possible. Highway message signs will also be used to encourage people not to stop and not to wear special eclipse glasses while driving. The glasses reduce the amount of light that enters the eyes so the sun can be safely looked at.

“We’re going to put messages on there: ‘Don’t look up.’ ‘Don’t look at the sun while driving,'” said Tom Johnson, emergency director for the South Carolina Department of Transportation.

People should get to where they plan to view the eclipse early, use special glasses to look at the sun while it is happening, and plan to stay there a while, Livingston said.

With so many people in South Carolina, Livingston said emergency planners are talking to the State Law Enforcement Division about anti-terrorism plans. The state will also activate its emergency management center as a precaution.

But overall, Livingston said planning for the eclipse over the past several months has been much more fun than his typical job of responding to disasters.

“I’ve got a big family. I have four kids and five grandkids and they are all excited about it,” Livingston said. “This is going to be fun.”