NEW : More than 3,000 flights delayed and almost 200 canceled . Reporter measures line more than a mile long at Midway airport . 11:35 90 % of travelers were expected to go by road .
NEW : More than 3,000 flights delayed and almost 200 canceled . Reporter measures line more than a mile long at Midway airport . About 46 million people were expected to travel for Thanksgiving , AAA says . 90 % of travelers were expected to go by road .