Most airlines now charge fees for everything from checked bags to changing your itinerary, resulting in billions of dollars of revenue for carriers and annoyance for travelers. And the fees are going up, with baggages fees up 67% since 2009, and cancellation charges up by 33% for domestic flights. Newly introduced legislation aims to curb these fee hikes.

The Forbidding Airlines from Imposing Ridiculous (FAIR) Fees Act is being introduced this morning by Sen. Ed Markey (MA) and Sen. Richard Blumenthal (CT).

The bill [PDF] doesn’t set specific limits or prohibitions on fees, but directs the Department of Transportation to bar airlines from imposing fees “that are unreasonable or disproportional to the costs incurred by the air carrier.”

Baggage fees and change/cancellation fees are explicitly called out as meriting consideration by the DOT, but the bill also directs the agency to look at “any other fee imposed by an air carrier relating to a flight in interstate air transportation.”

For checked bag fees, the bill would direct the DOT to examine both the costs of processing checked bags, and labor costs. The senators behind the bill question the logic of why airlines like American, Delta, and United charge more for your second bag than they do for the first. That may be because there is limited room on an aircraft and each additional bag not only takes up space but requires more fuel. The DOT would be tasked with figuring out if this does indeed merit the additional cost for second and third bags.

It’s a little more complicated with regard to fees for changes and cancellations, where the DOT would be expected to take into account a number of factors: the airline’s ability to fill seats after a change; whether passengers buying tickets after a change are paying more or less for their seats; and whether passengers who cancel their tickets are later booking travel on the same airline.

“Airlines fees are as high as the planes passengers are traveling on, and it’s time to stop their rapid ascent,” said Sen. Markey, who takes issue with the fact that fees have increased while fuel prices have dropped. “Airlines should not be allowed to overcharge captive passengers just because they need to change their flight or have to check a couple of bags. There is no justification for charging consumers a $200 fee to resell a $150 ticket that was cancelled well in advance.”

Sen. Blumenthal says that “runaway” airline fees are “anti-consumerism at its worst – in some cases doubling passenger fares despite plummeting fuel costs and soaring airline profits. A parent who wants to sit with his young child, a customer who wants to check or carry on a bag, or have WiFi, or a traveler who needs to change or cancel a reservation should not incur exorbitant, unnecessary fees on the whim of an airline.”

Our colleagues at Consumers Union are among the several advocacy groups that have come out in support of this legislation.

“Many add-on fees have reached a point where they are essentially a back-door fare increase,” says George Slover, senior policy counsel at CU. “This legislation aims to put some reasonable standards in place for these kinds of fees.”

This is just the latest in a string of recent pieces of legislation taking aim at airline reform. In February, Tennessee Congressman Steve Cohen introduced the Safe Egress in Air Travel (SEAT) Act, which would require the FAA to set a minimum size for airline seats. Last week, Sen. Chuck Schumer (NY) indicated that he would be pushing for similar seat-size reform by amending the currently pending FAA reauthorization bill.

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