As IMSA SportsCar Weekend activities were getting underway Thursday at Road America, IMSA president John Doonan drove a golf cart around the 640-acre property.

Immediately, he felt it. Something was happening. Something profoundly positive.

Campgrounds were quickly filling. Hungry, thirsty fans gathered at concession stands. Golf carts, scooters and e-bikes whirled around him. Three days before the green flag was scheduled to wave for the featured race, Road America was buzzing with activity.

A lifelong attendee of “America’s National Park of Speed,” Doonan knew the enthusiasm at the Wisconsin racetrack had reached new levels.

“I was blown away,” Doonan said. “I’ve been coming to this racetrack since I was 6 weeks old. I have not seen a crowd like this during that entire time. That’s 54 years. I’ve been a fan of endurance sports car racing all my life. I’ve been a fan of IMSA since its inception. I’ve never seen the momentum we’re experiencing now.”

Mike Kertscher, Road America’s president and general manager, saw it, too. Dozens of campers lined up at the gate at 7 a.m. Thursday, nearly 80 hours before Sunday’s main event. He joked with Doonan about the need to get cars on track immediately.