Sino-Singapore Tianjin Eco City — the world’s largest eco-city — is an experimental model for how Chinese cities could develop and solve some of the enormous problems facing them: permanent gridlock, a lack of water, and ruinous electricity bills.

General Motors is using Tianjin to work out if electric driverless cars can function in a normal traffic system, and road-test the next generation of vehicles: small urban cars that drive themselves but are safe in an environment full of unpredictable drivers, pedestrians and cyclists.

Other projects on trial include a low energy lighting system from Philips and rubbish bins that can empty themselves, sucking litter into an underground network, by a Swedish company called Envac.

The government-owned buildings in the city collect their own rain water for reuse, are powered by geothermal energy, have window shutters that move with the light, in order to keep buildings cool, and heating systems that use solar energy.