China's latest mode of public transportation is a bus, tram and train rolled into one. Its maker, Chinese rail transit firm CRRC, is calling it a "smart bus," but it's a lot more than that. Like a train, it's modular and carriages can be added on; but like a bus, it runs on the road. Amazingly, the carriage will follow a preset path and won't need a driver — but it won't need tracks to be laid, either.