I think the era of individually motorized mobility - no matter how the motor works - has to end at least in cities. All innovations we are talking about (end of combustion engines, "human logistics, driverless cars etc.) will ultimately lead to new forms of public or group transports. Owning a device for your personal mobility will be a total luxury, or will phase out completely. In cities. And this will make sense not only economically - read this article here.