The power of the road and all who live on it has attracted documentary-makers before. Both Chris Petit and Iain Sinclair’s ‘London Orbital’ and Marc Isaacs’s ‘The Road’ spring to mind when watching Italian filmmaker Gianfranco Rosi’s ‘Sacro GRA’ – the unexpected winner of the Golden Lion at the 2013 Venice Film Festival and the first documentary ever to nab the prize. It’s an oblique but engrossing collage of real lives lived in the shadow of the ring-road that circles Rome. Rosi presents a series of characters – an ambulance worker, an expert in tree parasites, prostitutes, a father and daughter and others – who live or work near the road (the title is a play on its abbreviated name, the GRA, and the Italian for ‘holy grail’). The most memorable sequence shows cemetery workers breaking open tombs and reburying bodies. Why? Who knows. Exactly what this chain-gang of varied experiences and opinions means is never clear, but the film’s stories have a mysterious, collective power that’s undeniable. Rosi’s film also benefits from the absence of an insistent voiceover or over-suggestive edits or juxtapositions. It’s an open work that is wistful and amusing, even if its depths might be more absent than hidden.