Travellers flying from New York's John F Kennedy (JFK) airport and New Jersey's Newark Liberty airport next summer will get to choose from fewer flights at the hours they most want to travel, but they are far more likely to leave and arrive on time. On Wednesday 19 December, US federal transportation officials announced that this summer there will be a cap of 82 to 83 scheduled flights per hour at JFK, plus four unscheduled flights, at the busiest times of day.

During some peak hours last summer, 95 flights were scheduled, and more than 105 would have been scheduled at those times next summer without this agreement, officials said. US transportation secretary Mary E Peters said the department would begin work immediately on a similar cap at Newark Liberty International Airport, to prevent extra traffic from flowing there.

At the briefing, Peters outlined the results of weeks of negotiations with airlines that produced a painstakingly pruned schedule during peak hours at Kennedy International Airport. She said travellers may even find more flights overall, as the measures eliminate last summer's epic delays.

Peters said the expected number of flights next summer would be about 50 higher per day than in the summer of 2007, though they would be spread somewhat more evenly through the day. Stopping the overload in peak hours will make for "significant reductions" in delays, she said.

Although the curbs on peak-time flights are likely to ease travel for many passengers, they are expected to affect a number of business and international travellers who typically fly in the morning or the evening, since some flights would be shifted to less congested times.

Major American airlines face no immediate threat to their existing landing slots, and said they were pleased with the decision to spread flights throughout the day, a move that could cut their costs by reducing delays.

DJ Gribben, general counsel of the Transportation Department, said that travellers were already paying a premium, because of unreliability. "If you have an important meeting in New York, you fly in the night before, because you can't count on the morning flights," he said. That meant costs for meals and hotel rooms, he said.

Peters said that as and when new technology gave Kennedy the ability to handle more flights - perhaps as early as the spring of 2008 - the additional landing slots created would go to the highest bidder. She did not answer the more contentious question of whether airlines now operating at Kennedy would have slots taken away and put up for auction.

This proposal has come in for severe flak. Senator Charles E Schumer (D-New York) has called the auction plan a "harebrained scheme". He says auctioning landing slots would raise costs for airlines that would be passed along to passengers.