DALLAS -- If you plan to travel around the upcoming holidays, prepare to pay a little more -- again.
Several of the largest U.S. airlines have increased a surcharge for travel on the busiest travel days to $20 each way, up from $10.
The surcharges apply to a large number of flights within the U.S. on more than a dozen peak days around holidays including Thanksgiving, Christmas and New Year's.
Tom Parsons runs the Arlington-based discount travel site Bestfares.com. He says Fort Worth-based American, along with Delta, United, US Airways and Northwest, all boosted their surcharge on some routes.
American spokesman Tim Smith confirmed the higher surcharges today. He saus that although airlines are filing the increases as a surcharge this time, "fares on those peak days have always tended to be higher." He calls it "a matter of supply and demand."
Comments have been turned off for this article.