( CNN ) -- For many fliers Sunday , it was holiday travel woes , round two . As of 6:30 p.m . ET , more than 3,000 U.S. flights were delayed and more than 190 were canceled , according to FlightAware.com . The line for security screening at Chicago Midway International Airport on Sunday morning was so long that reporter Denise Whitaker of CNN affiliate KOMO measured it : 1.2 miles . Traveler Sarah Crowder called it the worst she 's seen , prompting the Chicago Tribune 's Brian Cassella to call on the Transportation Security Administration to `` do better . '' Sunday is one of the busiest travel days of the year , as millions of people return home after the Thanksgiving holiday . `` This happens sometimes , '' Chicago Aviation Department spokeswoman Karen Pride said , according to CNN affiliate WLS . `` There was a period of time earlier this morning , between 6 a.m. and 8 a.m. , that lines were long because that is when most people are traveling for the holiday period . '' On Wednesday , the weather was widely blamed , as snow snarled traffic for parts of the country . But conditions were much better Sunday in many areas , with `` warmer and more tranquil conditions '' in parts of the country including the East Coast , CNN meteorologist Todd Borek said . The temperatures were in the upper 40s in Chicago . While a lot of attention goes to the airports -- where the interconnected flight travel system can have a domino effect -- the vast majority of Thanksgiving travelers hit the road . Ninety percent of travelers were expected to go by road , AAA said , helped by the lowest gas prices in five years . In all , more than 46 million people were expected to travel 50 miles or more for Thanksgiving , marking the highest volume since 2007 . 10 tips for Thanksgiving travel . `` The average distance traveled this Thanksgiving will be 549 miles roundtrip and Americans will spend an average of $ 573 during the holiday weekend , '' AAA predicted . How 's your holiday travel going ? Join the conversation on Facebook .
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 .