Travelers who are involuntarily bumped from a flight when it is oversold may start receiving better treatment next summer.

The Department of Transportation says it will propose doubling the fee that airlines must pay to travelers who buy tickets but wind up without a seat. The proposed increase would make the fee $400 to $800, depending on long the passenger has been delayed. The rule may go into effect next summer. First, though, the airlines and other industry players will have a chance to talk with government officials about the fairness of the proposed rule change.

Meanwhile, for passengers who are involuntarily bumped on domestic flights, the rules are as follows: If you're on another flight within an hour, you get nothing; within two hours, the airline pays you the equivalent of your one-way fare ($200 max); more than two hours later, you get 200 percent reimbursement ($400 max). These compensation rules are based on decades-old guidelines, and have not been adjusted for inflation over the years.

Passengers who relinquish seats voluntarily face different rules. There's no federal standard for that compensation. You're only guaranteed something, usually a flight voucher.