LIBERTY — State and local leaders gathered Monday in Randolph County to celebrate the designation of U.S. Highway 421 as the future Interstate 685. The event, held next to the under-construction Toyota Battery Manufacturing plant, featured the unveiling of new Future I-685 signs that will be going up along the route from Greensboro to Sanford. "Today's unveiling of the Future Interstate 685 sign is a true testament to the collaboration and teamwork that is fueling our economic momentum here in the Carolina Core," said Loren Hill, Carolina Core Regional Economic Development Director, at the event. I-685 will eventually run from…