We can choose to build a city that relies on technologies already in use in small areas across the world. Such as a public bike systems as seen in Paris with the Velib' system, or Barcelona, Lyon and countless other European cities. Or we could do something like what some Asian cities have done with the Oystercard system, they taken the use of a transportation card such as the oyster card way beyond what we can currently do in London. The card is now used to not only buy metro and bus tickets, but also groceries and other goods.
So now the question is, instead of re-inventing things that already exist, can't we take ideas that are still at the prototype stage and create a city that could accommodate for them? such as the flying cars that are currently being developed in Israel.
Below are a few ideas that i have found floating around the internet.