Delta on Wednesday joined other major airlines in hiking domestic flight baggage fees by $5 per bag to $30. The price hike follows similar moves by United Continental and JetBlue in August and comes as Congress is considering whether to require the US Transportation Department to assess whether airline baggage and ticket change fees are “reasonable and proportional.” Delta, United and JetBlue are now charging $30 for the first checked bag on domestic routes, up from $25 previously, and $40 for the second bag, up from $35. Airlines have cited rising costs as a concern, with high fuel prices and bumps in salaries and benefits for pilots, flight attendants and mechanics pushing up operating expenses. US airlines’ revenues from baggage and reservation change fees increased from $5.7b in 2010 to $7.5b in 2017. Other fees are not reported to regulators.<br/>