I am old enough to remember long distance driving before interstates. You would take a US highway from town to town where you would get caught in the local downtown traffic. The best towns had a bypass highway to avoid the downtown. I can’t imagine a modern interstate emptying into local streets for a trip through town. Anyhow here are some pictures of the Syracuse alternatives https://www.dot.ny.gov/i81opportunities/alternatives
My own idea would be to add a lane in each direction to I-481 and rename it I-81. I-81 would be renamed I-81 Business (with the green-and-white shields), and then the viaduct would be taken down and replaced with a wide boulevard. (There already is a street along each side of the viaduct.) The remainder of the old I-81 freeway would remain as is, ensuring speedy access to such places as Destiny USA.