If a significant amount of people is using google maps to decide their route, then solving queries from multiple users while coordinating the responses to each request is going to provide a strong advantage in terms of its optimization goal and will probably be an obvious feature to implement. The responses from the tool are going to be shaping the city traffic.

If this is the case, It's going to be extremely hard for humans to supervise the set of answers given by google maps (Of course, individual answers are going to be read by the end users, but that will be provide no insight on what it is really doing at a high level).

Having our example AI deciding where a lot of people is going to be at different times based on some optimization function looks really close to the idea of an agent AI directly acting on our world.