Mr. Osbaugh said the rooftop, which is expected to be completed next year, would look “a lot like the High Line, but not quite that industrial.” He said some vendors in the terminal had inquired about the possibility of serving food and drinks there.

The inclusion of a minipark fits with Mr. Osbaugh’s campaign to make the terminal less of a place to be slogged through and more of a pleasant conduit. He designed the ramps that carry passengers from arriving planes to the customs area to include glass walls that allow natural light to flood in.

In theory, he said, a traveler with nothing to declare to customs agents could get from a plane through baggage claim and out of the terminal in just 28 minutes. The electronic kiosks can scan passports and clear travelers in 45 seconds or less, he said. He added that JetBlue revamped its process for unloading luggage to make sure international passengers would not wind up waiting at carousels after passing through the checkpoints staffed by United States Customs and Border Protection.

Patrick Foye, the executive director of the Port Authority, said the project to expand Terminal 5 was estimated to have created 1,090 jobs, including construction jobs, and generated $74 million in wages and $325 million in total economic activity. He thanked JetBlue for helping to improve conditions and add capacity at Kennedy. Mr. Hayes, who will become JetBlue’s chief executive next year, said that he had traveled extensively and believed that “we have built something here that is one of the best terminals in the world.”

That sort of talk is a far cry from the words usually used in discussions about New York City’s airports. Vice President Joseph R. Biden Jr., while deploring the poor state of the country’s transportation infrastructure, famously likened arriving at La Guardia Airport to landing in a “third-world country.”

Mr. Hayes was quick to note that Mr. Biden had much nicer words for JetBlue’s home base. And he agreed with the sentiment Mr. Biden expressed when he visited the city last month and said, “It doesn’t matter how nice J.F.K.’s JetBlue terminal is if you can’t get in and out of the terminal quickly.”

Mr. Biden had joined Gov. Andrew M. Cuomo to announce a competition for ideas to improve the city’s airports. Mr. Hayes said “the challenge of J.F.K. is the surface conditions,” and he added that the hope was that someone would dream up a feasible way “to go from central Manhattan to J.F.K. in 30 minutes.”