There is a wonderful moment early in David Lynch’s new movie where the camera trailing Alvin Straight along the two-lane blacktop glides elegiacly upwards, above the road and the ocean-like cornfields, settling in the white-puff clouds above. Then it swoops back to earth, finding the 73-year-old widower literally within spitting distance of where we left him. He is, you see, undertaking his epic journey from Iowa to Wisconsin aboard a green, 1966 John Deere sit-on lawnmower. The Straight Story is a road movie at 4 mph.

And one that mainlines an initially disconcerting sweetness; a sentimentality even. It’s Blue Velvet without the sinister underbelly; anything but a lost highway. Alvin, who walks with two canes and enjoys failing eyesight, is off to visit estranged brother Lyle (Harry Dean Stanton). Lyle’s had a stroke and Alvin has to do the right thing. That’s what he tells grown, slightly simple daughter Rose (an excellent Sissy Spacek). He has to make this trip his own way: on that tiny, unprotected lawnmower. It took the real Alvin Straight - Mary Sweeny and John Roach’s screenplay is based on an incident from 1994 - two months.

And yet this remains identifiably a David Lynch Film. The extremity of his most recent work - the scarifying Fire Walk With Me; the terrifying derangement of Lost Highway - is displaced but not subsumed. The film relies on past association. It opens with the camera hanging tensely above Alvin’s single-story frame house, a corpulent woman sunbathing to one side, Rose leaving through the front. Slowly, deliberately, we crane in. It’s a set-up reminiscent of the second half of Highway, pregnant with menace and dread. Freddie Francis’ cinematography is jewelled as only Lynch films know how.

And yet despite that it remains a film that’s not even Edward Hopper let alone Dennis. Ain’t you afraid out there at night, asks a well-wisher, there’s all sorts of weird people about. In more typical times, in more typical David Lynch movies. But no backwards speaking dwarfs here. And yet the pacing and playing is archetypal. It’s a different world moving slowly, the director has said, and The Straight Story echoes his sentiment. Nothing is hurried, conversations evolve. The one burst of real action - on a steep hill - is doubly alarming.

Former stuntman Richard Farnsworth, carrying his first film since the equally charming The Grey Fox, gives an award-worthy performance as the infuriatingly genial Straight. And yet there’s grit in the grease as he gradually reveals himself to strangers and we pick up that he was a brawler, a drunk, father of fourteen, and a sniper in WWII. There’s a life here.

So there you have it, a David Lynch movie that does exactly what it says on the tin. A straight story, told with as little interference and obfuscation as his peculiar palette will allow. And yet there is resonance here: in the sly underplaying; the film-makers’ ability to ring tension out of slow, episodic drama; in Angelo Badalamenti’s gorgeous score; and in an end that says everything by saying nothing. Small, touching, humane. Seems David Lynch still has a few tricks up his sleeve after all.