Travelocity is taking fare transparency a step further with a new tool called Flight Navigator.

The tool will tell shoppers when three or fewer seats are available at a particular fare with an eye toward eliminating one of the "crap shoot" aspects of buying air travel.

It also will show a seat map during the shopping process, giving travelers the opportunity to choose a flight that has their preferred seating available. Some airline sites offer this feature, but until now shoppers on third-party sites had to purchase a ticket before they could see the seat map. Travelocity's seat map legend indicates which seats are considered "undesirable" due to proximity to toilets or inability to recline.

Travelers can select from a far more extensive list of alternate airports than was previously available. For example, Travelocity offers a choice of nine alternatives to St. Louis' Lambert Airport, ranging from Springfield, Ill. (84 miles away) to Bloomington, Ill. (141 miles away). Shoppers can select up to three alternatives, creating nine combinations.

Fare notes provide information on whether online check-in is available, bonus mile promotions and hotel add-on deals.

Henry Harteveldt, vice president at Forrester Research, previewed the new features and believes that Flight Navigator's ability to highlight three of eight different types of promotional offers or product feature listings -- coupon redemptions, dynamic package offers, premium cabin class or onboard services or amenities -- will create an awareness of real differences among airlines' products and services.

"As a result, a carrier could gain market share in a hotly contested city-pair,"he said. In addition, "Travelocity should be able to help airlines accomplish the miraculous: upselling a passenger."

Harteveldt expects that eventually airlines will have to pay to list offers or features in Flight Navigator, "similar to how packaged goods marketers pay for premium merchandising exposure like aisle end-cap displays."

Travel agents and airlines, however, looked askance at the "number of seats left" feature.

That information is frequently available to offline travel agents through the GDSs, but agents say the GDS feature doesn't always keep up with airlines' tendency to juggle inventory frequently.

That sentiment is shared by some airlines.

They note that inventories and fares change constantly, and they question whether the feature will have much impact on consumer behavior.

Flight Navigator will become available on Travelocity Business later this year.