Let's suppose we live in a city with open data and that these data, partly related to objects partly to people, can be exploited by third parties. The kind of services and the way a city can get smarter are amazing.
Look at the project DriveWave by the Senseable Cities team at MIT. Here the researchers have simulated the traffic flow across a main Boston intersection and studied the difference it can make if the red light regulating the traffic is replaced by a global understanding of self driving cars.
The position and "intention" of each car is part of the city data base, obviously updated in real time with each car position and direction. These data can be used to work out the best strategy for optimising the traffic flow and the simulation (look at the video clip) shows that indeed cars will no longer have to wait for the right of way at the intersection but can actually, and smoothly, drive across in perfect safety.
This decreases the travel time and the pollution/gas consumption due to idle wait at the red light and acceleration as the light turns green.
Of course this simulation is just a starting point. By having data on car position and knowing (even on a purely statistical base) the driver destination one can rearrange the complete traffic flow in the city.
At that point it becomes just a minor step to provide services that based on the driver urge (and willingness to pay) can speed up the travel by using shorter routes or increasing the priority, as if cars were packets on a network.
Indeed, if you consider the way packets are routed in a network you will see new routing strategies (not all of them sensible, since here we are talking about moving atoms, whilst a network is about moving bits: I bet you wouldn't like to be routed in your trip from Paris to Lyon to take a side trip leading you from Paris to Madrid and then on to Lyon, which might happen to your mail in its way from Paris to Lyon!).
A further observation is that once you have a seamless connectivity between the city atoms and the city bits you can sit in your couch and move into the world of bits simulating your travel through the city to see what is the best time for shopping, taking into account traffic, parking space, crowd in the mall and so on and even have this simulation being played in background to come into your perception as the time is about right to start your shopping day. There is basically no limit, but imagination, to what can be done once we move from the city of atoms to the one of bits and this will change both our experience of the city and our behaviour.
Of course the most crucial aspect to change our behaviour is to become aware of what is going on and what could be going on based on our decisions.