Like Shia LaBeouf’s door-to-door salesman Jake, who prides himself on becoming whatever his customers desire, Andrea Arnold’s fourth feature as writer-director is whatever you want it to be. For some, this story of a teenage Texas girl finding her feet among a travelling group of magazine sellers will be a timeless coming-of-age tale, a young woman’s search for a room (or trailer) of her own. To others, it’ll be a modern-day Easy Rider, a post-Larry Clark/Gus van Sant youthsploitation adventure in which “we explore America, we party – it’s cool”. Detractors may see little more than an overlong pop-video indulgence in which on-the-road outsiders sing along to a celluloid jukebox soundtrack. For me, however, this is Arnold’s best work since her 2006 feature debut Red Road, an electrifying odyssey which mixes the vérité grit of Ken Loach’s sociopolitical parables with the awestruck natural beauty of Terrence Malick’s rural cinematic dreams, all filtered through the eyes of an irrepressible heroine whose experiences are at once singular yet universal.

We first meet 18-year-old Star (a revelatory performance from screen newcomer Sasha Lane) scavenging for food in a bin while caring for two young kids. Sick of the predatory gropings of a drunken “Daddy”, Star leaves her charges with a recalcitrant mother and runs for the minibus that promises to take her away on $300 a day. The only conditions are that she will work hard and that no one will miss her. Dazzled by the piratical, rat-tailed Jake (LaBeouf’s most convincing performance since 2006’s A Guide to Recognizing Your Saints), Star learns the tricks of the trade – the door-knocking deceptions, which at first appal her but gradually start to appeal. “So you’re a southern girl,” says steely crew-manager Krystal (Riley Keough, channelling her grandfather Elvis Presley’s moody stare), “a real American Honey like me.” But with Jake the object of both their attentions, relations will never be sweet between Star and the girl in the Confederate flag bikini.

Partly inspired by a 2007 New York Times article about the brutal on-the-road existence of “mag crew” kids, American Honey revisits many of the themes that have haunted Arnold’s work since the days of her Oscar-winning 2003 short Wasp – social inequality, dangerous attractions, defiant spirits. Yet with its dappled sunlight and crystalline lens flare, Arnold’s first film set outside the UK also mixes in elements of what she calls the “mythical America of westerns and road movies”. Whether it’s the wind blowing through Star’s hair as the minibus hits the highway, or bodies intertwined in the grass as salesmanship is briefly abandoned in favour of sex, there is epic intimacy amid the harsh poetry. Cinematographer Robbie Ryan shoots in the squarer Academy ratio, which has been Arnold’s signature since Fish Tank, but his superb use of the 4x3 frame makes the image seem taller, rather than narrower, than more popular widescreen formats. There’s a lot of sky in American Honey, a sense of expansiveness that marries shallow-focus closeups of pierced and tattooed skin with breathtaking vistas that seem to sweep upward towards the stars.

Somehow, this frame creates a safe environment for the cast, many of whom are first-timers picked from shopping malls and skate parks. Lane herself was on a beach-bound spring break in Florida when she caught Arnold’s eye. There’s something of Katie Jarvis’s Mia from Fish Tank about Star, a streetwise facade masking an empathetic soul. In an unforgiving world she is a nurturing presence, constantly saving the omnipresent insects that fall into water and fly into windows, struggling to protect the firefly spirits that thrum throughout the drama. And while Star may climb with reckless abandon into passing cars and trucks (from an open-top full of good ol’ boys to a cattle truck en route to an abattoir), we never doubt her shimmering indestructibility. Jake may have got a gun, but it’s Star who knows how to handle one.

As thumping hip-hop blares from the bus, American Honey reveals its true roots in the dreamy fantasias of the musical. In an early scene, Jake seduces Star from afar to the strains of Rihanna’s We Found Love, turning a supermarket into a disco in a sequence that rivals the vibrancy of the Diamonds dance from Girlhood. Later, the call-and-response of E-40’s Choices (Yup) soundtracks a bonding car-park ritual, while a singalong to the Lady Antebellum song from which American Honey takes its title echoes the glorious Tiny Dancer sequence from Cameron Crowe’s Almost Famous. Some may see this journey as bleak, but it’s The Wizard of Oz and Star Wars that (g)litter these kids’ dreams, placing a yellow brick road beneath their feet, a distant Death Star above their heads, and a tough but tender sweetness in their hearts.