Not much reasonable technology is available for the smart cities yet. Regarding MCU's currently 8bit class MCUs are used, but 32bit class will be needed for smarter solutions, no one accepts to pay the dif. For memories FLASH is not an enough solution regarding its slow and little write cycle, only a hundred thousand times will be exhausted in weeks, but FRAM could be a nice solution but again the price dif..
Actually I see this smart city trend as a very long-term and gradual one, which started certainly more than 100 years ago.
Consider street lighting. There used to be a guy whose job was to walk up and down streets every evening, to light the gas lamps. Then every morning to shut them off. Then the lights became electric, and without anyone having to visit each one, they could be lit and shut off. The individual sensors in each light were installed, and they each light and shut off as local conditions dictate.
Isn't that already a "smart street lights" trend?
Or how about taxicabs. Used to be, you either had to physically go to a cab stand, or you could call the phone at the cab stand, and a cab would come pick you up. For decades now, that old scheme has been updated progressively, first with radio dispatch, then with computer dispatch.
Most city services have been evolving technologically for a very long time, "making cities smarter." I don't think it should surprise anyone if this trend continues.
Its an interesting idea on how to use our technology to enable the resources of a city to better anticipate the needs of the residents and visitors. I think if we spend some time integrating the information, then the applications can be created to identify people, especially those with handicaps and establish a control application around that person's path through the city to open doors, call cabs, alert loved ones, etc.
Could make going to the city a more enjoyable experience and lesson the "concrete jungle" perception.
Just a thought,