Maintenance is an unfashionable word. But as Chris Bowlby discovers, keeping our infrastructure in good condition is one of the most crucial and creative challenges we face. Key assets such as concrete bridges built in the early post-war decades are crumbling, and may be what one expert calls 'ticking time bombs'. And all kinds of systems, even in the digital world, still need maintaining well. But all the focus for politicians and many engineers is on brand new infrastructure, not sustaining the vital assets we already have. So how can we learn to value maintenance in a radical new way?

Producer: Chris Bowlby Editor: Jasper Corbett