In Illinois, they’ve been building an extension to I355, a connector ‘interstate’ highway. It’s slated to open next month.
As a fundraiser to build a multi-use trail, they’re opening up the road to cyclists for 3 hours, much as they do Lake Shore Drive once a year for a closed-to-traffic event. I’ll just quote the Roll the Tollwaysite:
Roll the Tollway offers a one-time, car-free bicycle ride on the new South Extension of I-355 before it opens to car traffic. Join thousands of cyclists for more than three hours of car-free bicycling on a 20-mile loop fully supported with rest stops and plenty of volunteers.