But will it recapture the feel of the old bus? And should it? In the politically heated, stressed-out, pressed-for-time atmosphere of a general election campaign, the weirder campaign bus moments of yore may be gone forever.

Image Mr. McCain, accompanied by his wife, Cindy; his mother, Roberta; and Gov. Haley Barbour of Mississippi, arriving in Jackson, Miss., in March on the campaigns chartered jet. Credit... Mary Altaffer/Associated Press

This campaign bus was, after all, a recreation of the 2000 model, which propelled his energetic but unsuccessful insurgency against George W. Bush.

This time around Mr. McCain started out as the presumed Republican front-runner, and he initially ran a more cautious, conventional campaign. But when his campaign nearly went broke last year, and he plummeted in the polls, he retooled and went back on the bus. It worked in part because it was an efficient way of campaigning in his must-win state, New Hampshire (and it was relatively cheap), and it allowed him to loosen up as a candidate.

There were glimmers of the old bus style during daylong bus rides when, after the newsier queries were exhausted, Mr. McCain would discuss with reporters the story of Ray Bradbury’s “Martian Chronicles” or the Korean War, or gossip about Senate colleagues or talk about his love of the group Abba.

These days the bus trips are usually short hops between airports and campaign events, and most of the seats are reserved for local reporters. Interactions on the bus are more likely to be focused on news, sometimes to Mr. McCain’s discomfort  as when he was pressed on a recent ride through Pennsylvania on how he thinks he can hope to pay for his tax cuts by eliminating pork barrel projects worth much less.

Most of his interactions with the national reporters these days come in the few formal news conferences held each week, at which the questioners and answerers alike speak into microphones and the relentless follow-ups of the bus are difficult.