Three of the five cyclists killed recently in London died on or near Cycle Superhighway 2, a cycle-path route running from Aldgate in the City to Stratford in the east of the capital. Rigged with a camera mounted on his helmet and another on his bike, Peter Walker rides the route. It takes in some of London's worst cycle infrastructure – lorry-choked roads and just a blue-painted lane for protection – and the best, with a new, fully segregated section at the end