Over the last Christmas holidays, several airlines instituted a “peak travel surcharge” for January 2 and December 26. While this was annoying to passengers and travel agents alike, the carriers justified it by saying that those dates were premium with high demand.

Now, in the past, the way airlines have dealt with peak travel dates was either showing the flights sold out for lower fares, or flat out saying there are blackout dates to the lowest-fare tickets.

Not anymore. Especially since this new method allows them to lure passengers to begin the buying process with fares that will never be available.

Here’s just one example or surcharge overload from American Airlines on a fare between San Francisco and Chicago. American is not the only culprit — virtually all of the mainline carriers are doing the same.

The basic fare, coded SA14ERD1, is $206 one way. (Although for some reason the total is always $10.70 higher with non-advertised taxes.)

Now the real airfare fun starts with screen after screen of surcharges.

Some of these surcharges are clearly for busy travel dates. For example, AA charges an additional $27.91 for the Sunday and Monday after Thanksgiving and the same amount for the Sunday after Easter, or on December 23, just before Christmas.

But other surcharges just seem to fall in the category of “Because we can.” There can be little other justification.

All in all, AA lists over 25 different peak surcharges for this SFO/ORD flight. The surcharges seem to have no rhyme or reason.

Here are just a few examples right from the AA screen:

A SURCHARGE OF USD 18.60 FARE COMPONENT WILL BE ADDED TO THE APPLICABLE FARE FOR TRAVEL ON MON/THU/FRI/SAT/SUN FROM 10JUN 10 THROUGH 28JUN 10.

A SURCHARGE OF USD 9.30 FARE COMPONENT WILL BE ADDED TO THE APPLICABLE FARE FOR TRAVEL ON TUE/WED FROM 15JUN 10 THROUGH 30JUN 10.

Here are some surcharges to flights scheduled later in the summer:

A SURCHARGE OF USD 18.60 FARE COMPONENT WILL BE ADDED TO THE APPLICABLE FARE FOR TRAVEL ON MON/THU FROM 01JUL 10 THROUGH 16AUG 10.

A SURCHARGE OF USD 18.60 FARE COMPONENT WILL BE ADDED TO THE APPLICABLE FARE FOR TRAVEL ON FRI/SAT/SUN FROM 02JUL 10 THROUGH 15AUG 10.

A SURCHARGE OF USD 9.30 FARE COMPONENT WILL BE ADDED TO THE APPLICABLE FARE FOR TRAVEL ON TUE/WED FROM 07JUL 10 THROUGH 11AUG 10

In short, almost all of July and August dates are “peak.”

Now, in general, the final ticket price total will show up before a ticket is actually purchased. But for travelers shopping around online or with an agent, the odds are most of the final fares are going to be an unpleasant surprise only discovered at the end of the buying process.

These peak surcharges also aren’t going to trumpeted in the those big full-page newspaper ads.

From a travel agent perspective, it puts us in the “bearer of bad news” category, and or in the the situation of having the client inform us that this price is higher than they saw online. (Which often results in them going online again, and finding out that the surcharges are there too.)

I have nothing against airlines trying to make a profit, which I realize sometimes involves fees. But these seasonal surcharges are neither optional (like checked bags, food, and preferred seat assignment), nor do I think they are fairly disclosed.

It’s no wonder the airline industry is held in such low esteem by their consumers.