Uploaded on 2018-05-13 by Kristin Atwood

This is a picture of the Canada Revnue Agency headquarters building in Ottawa, Ontario. There are two sources of data in the picture that can make the invisible visible. First, there are traffic lights. Traffic lights contain cameras that can be used to analyze the flow of traffic along the street, as well as pedestrian traffic, since pedestrians can affect the flow of traffic by pressing the walk buttons and changing the light schedule. The second source of information is the parking lot. This is a gated lot that requires you to acquire a ticket in order to park. The machine monitors how many tickets are distributed and through that you can determine the volume of cars that park and how that varies by time of day or day of week. This gives you a sense of how many people come to this part of town and stay for a length of time, vs. driving through (which is what you get from the traffic lights). Together these provide an indication of how people move in and out of this area of the city.