On the face of it, Lean on Pete is a plain, pure-of-heart example of what some might call the “boy and his horse” genre. The fourth film by the humanist British auteur Andrew Haigh – whose sure, sensitive hand guided the Nottingham-set gay heartbreaker Weekend and the late-life marital crisis study 45 Years – might be his most narratively classical to date, following the enterprising, orphaned Oregon teenager Charley (Charlie Plummer) and his ageing steed Pete on a trek across middle America, in search of sanctuary with an estranged relative in Wyoming. Delicately adapted from Willy Vlautin’s 2010 novel, it follows classical narrative arcs of both the coming-of-age story and the great American road movie, yet with precious little of the romanticism and sentimentality that tends to accompany them: Haigh, rather like his stoic protagonist, keeps his eye quietly and pragmatically on the destination.

Beneath that simple, serene surface, however, lies a spirit of roiling anger and discontent, as Haigh’s camera perceptively captures a landscape riven with poverty and social inequality: crowded soup kitchens, ill-stocked convenience stores cruised by can-filching shoplifters, and rusty trailers spilling out on to the pavements, their inhabitants gnarled by hunger, brutality and substance abuse. Charley drifts through it with his head down, resorting to theft and violence where necessary to get by, and with little display of overt shock or pique: this is all he’s ever known, after all, and he’s learned, perhaps prematurely, to roll with the punches. Without resorting to clunky commentary at script level, Lean on Pete seethes on his behalf: its images and characters alike are born of a broken America.

Lean on Pete’s 21st-century update of the Oregon Trail is far from the first film to examine social discord and disarray through the prism of a single interstate journey: Haigh himself describes it in a recent Sight & Sound interview as “a modern version of the American myth”, citing a break from tradition in that Charley goes “the opposite way, not looking for freedom, but for security and stability.” And Haigh certainly isn’t the first foreign film-maker to bring a wary or critical eye to the land of the free. From Jean Renoir (The Southerner) to Wim Wenders (Paris, Texas), from Mira Nair (Mississippi Masala) to Antonio Mendez Esparza (the shattering recent festival hit Life and Nothing More), some of the most powerful portraits of the American Dream’s scrappier, more fragmented reality have come from outsiders — their perspective perhaps inflected with their own sense of alienation, and their sympathies duly directed toward those US cultures and classes on society’s fringes.

Yet Haigh is the latest in a notable recent run of British directors to turn their gaze to America – middle America, in particular – with a mixture of wonder at its vast geographical and spiritual strangeness and sceptical inquiry into its social malfunctions. Lean on Pete would make a complementary double bill with Andrea Arnold’s swirling 2016 odyssey American Honey, also her first foray across the Atlantic after three astute portraits of particularly British flavours of unhappiness.

Like Lean on Pete, Arnold’s film follows a rootless teenager in search of some form of familial belonging – in her case, with a gang of likewise aimless youths hawking magazine subscriptions across the midwest – but is supersized and expressively unruly where Haigh’s is contained and watchful. Arnold decides to meet America’s gaudy excess on its own terms, though through its kinetic, pop-scored energy, the film simmers with anger, even revulsion, at the social corruptions and injustices it encounters along the way, whether in the shape of sexually threatening cowboys, hypocritically Bible-thumping suburban madams or starving, dumpster-diving makeshift families. It premiered six months ahead of Donald Trump’s presidential victory, but pointedly profiled the belt of red-state America that enabled it.

Some American critics took issue with Arnold’s ugly-beautiful portrait as a kind of inauthentic burlesque of their country, skewed by foreign preconceptions and blind spots — though not as many as those who took against Martin McDonagh’s Oscar-winning Three Billboards Outside Ebbing, Missouri, which weathered a firestorm of political and moral debate, backlashes and counter-backlashes, between its rapturous first reception in Venice and the Academy Awards.

McDonagh would probably be the first to admit that his all-guns-blazing parable of midwestern revenge and arguable redemption wasn’t deeply embedded in the culture and vernacular of small-town Missouri. Centered on a doughty single mother, Mildred Hayes, and her one-woman crusade against the unidentified man who raped and murdered her daughter and the male cops who have failed to solve the crime, it’s a carnival of grotesques in which characters largely speak the hard, heightened, expletive-riddled McDonagh dialect heard in all the Irish-British playwright’s work – and has a subjectively twisted worldview to match. Many went with his selective vision; others found his film fatally tone-deaf to complexities of American race relations, class conflicts and police resistance movements. On the debates went, with US critics on both sides – though it’s perhaps telling that the film enjoyed its two biggest hauls of the awards season at Britain’s Baftas and the Hollywood Foreign Press Association’s Golden Globe awards. Outsiders unite.

Restrained, humane and trading in universal needs for nurturing and belonging, Lean on Pete won’t prove remotely as divisive, but its outside gaze is just as integral to its storytelling and its aching emotional payoff. You can understand the lure of America to British film-makers: the sheer scale of its geography and population is irresistibly inviting to restless foreign artists in search of new subjects and stories, with a global reach and recognisability that closer-to-home stories can rarely find. Haigh, Arnold and McDonagh have all benefited richly from the change of scenery – not to mention Lynne Ramsay, whose US-set films We Need to Talk About Kevin and You Were Never Really Here both offer sharp, trauma-shaken meditations on uniquely American cultures of violence and domestic dysfunction.

One hopes, however, that their voices, and others like theirs, aren’t lost to a Brexit-era Britain with more than its own share of crippling social damage, disintegration and prejudice to ponder: there are many English Honeys and Three Billboards Outside Ebbsfleets demanding to be made, and the UK industry can ill afford to export all its anger.

• Lean On Pete is released in US cinemas on 6 April and in the UK on 4 May