When it comes to roads, bridges and buildings, are bigger infrastructure projects better? Ed Butler reports from on board China's fast-expanding rail network, and Manuela Saragosa speaks to Bent Flyvbjerg of Oxford University's Saïd Business School about the merits of going big. Plus could tech companies read your mind? Martin Talks, digital trends expert for Google, discusses the technology. (Photo: A roads system in Guangzhou, China. Credit: Getty Images)