Several Major Airlines Raise Fares on U.S. Routes, Again.

Bad news for travelers. Airlines fares are going up. As if they didn't charge enough for fees, several U.S. airlines are increasing their fares after a three-month break from increases.

Airlines took a break from increasing fees as fuel prices were low, but now fares are going up again. Last week, United Airlines increased their base fares up to $10 per round trip in the U.S. Now other airlines are doing the same.

On Thursday, JetBlue Airways and Virgin America also raised their fares. Over the weekend, Southwest Airlines decided to raise their fares by $4 to $10 round trip for most domestic routes. Being that Southwest carries the most passengers in the airline industry, other airlines follow their fare decisions.

"Southwest participation virtually assures the hike will stick," said Rick Seaney, CEO of FareCompare.com.

Now Delta Airlines, US Airways, and American Airlines are upping their prices as well.

"Airlines only raise fares when the competition does the same and they feel consumers won't balk," says Rick Seaney, CEO of FareCompare.com, as quoted by USA Today. "They attempt from time to time to test both competitors and consumers. (It) appears for now they are comfortable with forward-looking bookings."

For many months, airlines weren't able to raise their prices due to fuel prices being low and a period of economic uncertainty. However as airlines cut the number of flights that they have, they are able to raise their prices.

This increase is the fourth this year, but it is far less than the nine fare increases in 2011.

Strangely, this increase comes as airlines start to move up their fall fare sales. Traditionally, fall travel sales don't begin until the school year starts in September, but several airlines are starting their fall sale on August 20. Fares will see a 10 to 20 percent decrease on domestic seats for some fall routes, which is usually a slow time for travel.

Seaney doesn't see more fare increases occurring in the near future. "Given the slower fall season, starting at the end of August, it is unlikely we will see another hike in the next few months," he told USA Today.

Just because the airlines have raised their fares doesn't mean that they won't continue to have sales.