This post will be the first showing some of our own work at the Cities Centre. These maps were made a while ago, when we were first investigating the use of ArcGIS’ Network Analyst. We found that, when making a network, ArcGIS will also give you a shapefile with all of the intersections demarcated as points. We took these points and ran a simple kernel density tool to produce a map showing density of intersections in the Greater Toronto Area.
This is the map of the intersection densities. There are several interesting stories told by this map. For example, the density of intersections closely relates to locations of development with downtown Toronto being the most dense, and with pockets of development popping up as splotches disconnected from the central city.
Also interesting is the difference between the older part of the GTA (i.e., downtown Toronto) and the relatively newer suburbs. Downtown Toronto developed from the late 1800′s to the present, while newer areas of the GTA, such as Mississauga, have been developing since the 1950′s and 1960′s (perhaps even later)
Another interesting aspect of this map is that you can easily discern large industrial areas and parks from the rest of the city. The map below shows three spots that have very low densities than the areas around them:
Why is intersection density useful? Some research has linked high intersection densities to better walkability. Ped Shed has a great post on intersection density (Link) that outlines the pros and cons of using intersection density as an indicator, as well as its relevance in the study of walkability.
We’d love to hear what you think: leave a comment below!