Answer:
Direct route
If I was traveling from Florida to the Great Lakes, I would take the most direct route, which would be to head north through Georgia, North Carolina, Virginia, West Virginia, Pennsylvania, Ohio, and Michigan.
From Florida, I would take I-75 north to I-85 north, following that up into Virginia.
From there, I would take I-81 north into West Virginia, then I-80 east into Pennsylvania.
Once in Pennsylvania, I would take I-79 north into Ohio, then I-90 east into Michigan.
This route is the most direct route and will get me to the Great Lakes the quickest.