People are trying to overpack their carry-on bags to avoid checked-baggage fees, though the airlines strongly dispute this.

人们试图随身多带行李以免除托运费，但航空公司强烈反对这种做法。

Another factor may be that more people are trying to overpack their carry-on bags to avoid checked-baggage fees, though the airlines strongly dispute this.

另外一个因素可能是越来越多的人为了不交行李托运费而尽量随身携带更多东西，尽管航空公司强烈反对这种说法。