Fewer passengers are expected to fly this summer, traditionally the peak season for air travel  partly because of the soft economy, of course, but the difficulty of traveling may also be a factor.

The Air Transport Association, an industry trade group, predicts 211.5 million people will fly between June 1 and Aug. 31, down more than 2 million passengers from last year’s record of 213.5 million.

Flights seem to be disappearing by the day.

Last week, Mesa Air Lines, a regional carrier based in Phoenix, said it would shut down Air Midwest, a regional subsidiary, on June 30. The move will eliminate service to 16 small cities in the 10 remaining states where Air Midwest, which had already cut flights, still operated.

Eliminating flights is the latest move by the airlines in a cost-cutting drive that also has led to ticket prices climbing 10 times this year and new fees, from charges for checking extra bags to changing itineraries.

Almost every major carrier, from American Airlines to Delta Air Lines and US Airways, is crossing cities off its list, leaving passengers with fewer choices than a year ago.

Some travelers have no choices, but it is not for lack of trying by city and state officials. After Hagerstown briefly lost its eligibility for a government program called the Essential Air Service last year, Maryland’s Congressional delegation helped win an extension that allowed Hagerstown, as well as Lancaster, Pa., and Brookings, S.D., to remain in the program until Sept. 30.

The Essential Air Service program was created in 1978, when the airline industry was deregulated, to ensure that communities in rural and remote areas would be linked to the nation’s air system.