Car-sharing's promise of clean cities

Would you hand in your car, if you knew that public transport in your city could be completely overhauled and made more attractive?

Imagine if you could order a shared taxi with your smartphone, which would bring you door-to-door to your destination, without any transfers. You could book it in real-time, with a maximum waiting time of ten minutes, and you'd share it with a maximum of five others.

Or perhaps you'd opt for the taxi-bus, which you would have to book thirty minutes i...