“It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness … ” David Lodge’s 1975 tale of transatlantic donswapping, Changing Places, carries a Dickensian subtitle – A Tale of Two Campuses – that hints at the revolutions set in motion by an academic exchange programme between the University of Rummidge and Euphoric State University in California.

It comes as no surprise that Lodge’s British scholars are keener for a move to the sun-drenched campus on the San Francisco Bay than their American colleagues for a transfer to his fictional redbrick loosely modelled on Birmingham. In the end, the academically unremarkable but securely tenured Philip Swallow – an idle underachiever in the mould of John Williams’ Stoner – takes off for six months to swap jobs with the prodigiously productive, high-flying American Morris Zapp, who only takes the job in order to delay his divorce from zealous feminist Desirée. The two professors settle into their alter-ego existences with relatively little turbulence: moving into each other’s houses, driving their cars, sleeping with their wives … Much like Malcolm Bradbury’s earlier Stepping Westward, the British academic’s journey to America is first and foremost one of sexual liberation.

Changing Places is the first and most striking of Lodge’s Campus Trilogy, and was followed by Small World in 1984 and Nice Work in 1988. It’s the most formally experimental of the three, with an epistolary section and a chapter composed of newspaper cuttings, clips from manifestoes and student handouts. The final scene, in which the ménage à quatre convene in a New York hotel room to “sort out their futures”, is written as a screenplay.

But beyond its formal inventiveness, the novel is powered by journeys, especially journeys taken by air – as the narrator observes, “Flying is, after all, the only way to travel”. The Campus Trilogy charts the rise of the literary critic as international superstar, a phenomenon inextricably bound up with the rise of air travel in 1960s and 70s, after airline deregulation saw prices dive and passenger numbers soar. We see this most obviously in Small World, where the academic conference circuit becomes a proviso for amorous pursuits, taking in Tokyo, Jerusalem, Honolulu and beyond – a glamorous excuse to visit countries that were out of reach for the vast majority of holidaymakers, allowing the participants to “indulge themselves in all the pleasures and diversions of travel while appearing to be austerely bent on self-improvement” (and get their expenses paid to boot).

Yet while the denizens of that novel are constantly hopping on planes en route to their next far-flung location, the experience of air travel itself is rendered with far more detail and affection in Changing Places. In an era of plastic cutlery, increased security and decreased leg room, the joy of the earlier book is the way that it captures some of the excitement of international travel.

The novel opens with Zapp and Swallow crossing paths above the North Pole, “protected from the thin, cold air by the pressurised cabins of two Boeing 707s, and from the risk of collision by the prudent arrangement of the international air corridors”. Lodge renders the act of flying so poetically – the rhythmic rising and falling of aircraft; the unique blend of anxiety, exhilaration and sangfroid exuded by passengers; the intricate latticing of the atmosphere by innumerable contrails – that it comes to seem almost an art. Now the lattice that connects us is digitally immediate we travel all the more, but we’ve lost this thrill of adventure. It’s oddly touching to read a novel where journeys are so inherently exciting, and it makes the book both consummately funny and poignantly elegiac.

Like all holidays, the exchange has to finish: “that’s something the novelist can’t help giving away, isn’t it, that his book is shortly coming to an end? It may not be a happy ending, nowadays, but he can’t disguise the tell-tale compression of the pages”. Lodge resists the temptation of the explosive ending, even though, as he quips, “It would have solved a lot of problems, of course. A spectacular finale to our little drama”. Instead, he leaves it unclear whether Swallow or Zapp will elect to make the swap (of jobs or wives) permanent. The meeting in New York involves discussing “every possible resolution”, but, as Swallow posits, “it can just … end” – which is precisely what the novel does. Until, of course, you reach for the sequel …