U.S. airlines, already fighting delays affecting a fifth of all flights, will confront a 31 percent surge in passenger traffic within eight years, the government said yesterday.

Passenger boardings will grow 3.8 percent this year to 768.4 million and surpass 1 billion by 2015, the Federal Aviation Administration said at its annual forecast conference in Washington.

The report underscores pressure on U.S. regulators to overhaul the nation's 1960s-era air-traffic-control system, at a cost of as much as $22 billion, to head off aerial gridlock.

"Delays cost the U.S. economy some $15 billion" in 2005, Glenn Tilton, chief executive officer of UAL Corp.

, United Airlines' parent, said at the conference. "Our customers directly bear the cost."
By 2020, takeoffs and landings will swell 59 percent at New York's John F.

Kennedy International Airport, 54 percent at Los Angeles International Airport, and 38 percent at Hartsfield-Jackson Atlanta International Airport, the FAA said.
"Passengers should look at these increased numbers with trepidation," said David Stempler, president of the Air Travelers Association, a consumer group based in Potomac, Md. "Unless we can fix the air-traffic-control system, we will be staring right into the face of gridlock.

"
The mushrooming passenger numbers are equivalent to adding two airports the size of Dallas-Forth Worth International each year, FAA Administrator Marion Blakey said in an interview.
The forecast shows "the definite need for a solution and a new air-traffic system that can handle this," she said.
Arrival delays in January soared to 24.

2 percent, the highest in that month since 2000, according to the U.S. Bureau of Transportation Statistics.

For all of last year, about 22.6 percent of flights arrived at least 15 minutes late.
Enplanements, the number of boardings for domestic and international commercial flights, will reach 1 billion in 2015 and grow 3.

5 percent a year through 2020, the FAA said in its forecast.
Blakey is pressing Congress for a 40 percent increase in FAA capital spending, to $3.5 billion a year by 2012, and is asking lawmakers to approve a new method for financing air-traffic control.

The FAA chief asserts that a user fee would be more reliable than the current method of taxes on passengers, fuel and cargo. The change is opposed by owners of private aircraft and business jets. The current mix of taxes that funds the agency expires Sept.

30.
One of the FAA's top equipment priorities for handling traffic growth is known as ADS-B, for Automatic Dependent Surveillance-Broadcast. The system would give pilots position reports about other aircraft and increase airspace capacity by allowing planes to fly closer together.

The FAA plans to spend $86 million on the system next year, rising to $156 million by 2011.
Three companies, Lockheed Martin Corp., Raytheon Co.

and ITT Corp., are competing for an ADS-B contract the FAA expects to award in July.