Travel is an ice-jammed nightmare now, but travelers have been getting used to more problems: Last year was one of the worst for airline reliability of the past five years.

Delays went up and more flights were canceled in 2013 than 2012, even though airlines again reduced the number of flights crowding airports, according to FlightStats Inc., which tracked more than 8 million trips last year. About 78% of flights on U.S. airlines arrived on-time last year, down from 80% in 2012.

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