The Illinois Department of Transportation is warning of heavy traffic across the state -- especially in southern Illinois, near Carbondale -- when a total solar eclipse takes place on April 8.
"The 2024 solar eclipse will be visible over approximately 128 miles of Illinois April 8," IDOT said in a post. "Totality enters Illinois as it crosses the Missouri state line southwest in Carbondale at 1:58 p.m. The eclipse will follow a diagonal line crossing over Fairfield and exit Illinois at Mount Carmel at 2:06 p.m."
In the Chicago area, approximately 95% of the solar eclipse will be visible. And while many will be able to see a partial version of the eclipse in Northern Illinois, hundreds of thousands are expected to travel downstate and chase the eclipse's path, resulting in potential traffic impacts.
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"Crowds of 100,000 to 200,000 are expected to come to the prime viewing area in southern Illinois," the agency warned. "All roads in and out of the area are expected to have heavy congestion in the couple hours after the eclipse."
IDOT noted that I-57, which travels from Chicago to the southern tip of the state, is the direct interstate with access to the path of totality. U.S. 45 runs through the middle of the path of totality, and Illinois 1 and Interstates 64 and 70 will also provide access IDOT said.
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"Prepare for traffic congestion before, during and after the eclipse," the agency warned, adding that it expects heavy traffic on rural roads, interstates and major highways leading to and from Chicago, St. Louis and other cities.
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Experts also warned people to turn on their headlights if driving during the event.
"Even though it’s a partial eclipse over Chicago, the skies are still going to get darker, with more than 90% of the sun getting covered," NBC 5 Meteorologist Kevin Jeanes said. In the eclipse's path of totality, skies were expected to get "much darker," Jeanes said.
Those in Midwest who are traveling during the eclipse are encouraged to hit the road with a full tank of gas, a charged phone and bottled water. IDOT also warned drivers to be cautious, as "a large number of pedestrians" were expected to be near roads.
"If you’re in a vehicle, don’t stop along roads or bridges," the agency said.
And while many parts of Illinois will need eclipse glasses to view the spectacle safely, IDOT warned against wearing them while driving, as they block out almost all visible light.
"Don't ever take photos, videos, or wear 'eclipse glasses' while driving," the agency stressed.