I was poking around the Stats NZ site the other day (unrelated to my post on central city employment) when I came across this neat interactive visualisation of the Journey to Work data from the last Census. By clicking on any Area Unit it will show how many people commuted to and from it from every other Area Unit. People commuting to an area are shown in blue while people commuting from the area are shown in Brown while people who live and work in the same area unit aren’t shown on the map but are indicated on the table to the right of the map.
The tool is still in beta and one issue I’ve found is that the thickness of the line can be a bit misleading. It seems the thickness is based on passing a threshold for the numbers of people moving between two area units. As such less than 100 people is shown as a thin line, between 100 and 300 as a medium line and above 300 as a thick line. That said here are a few examples and some interesting observations from briefly playing with the tool.
The difference in the distribution of trips to the eastern and western sides of the CBD are quite pronounced. As mentioned above some of that will be due to there being more jobs in on the Western side as well as the thresholds that have been set but I wonder if there are other factors at play
A chart to the right of the map also provides information on how many travelled to, from or live and work in the area.
As you would expect, most people working in other employment centres tend to live in the surrounding suburbs, an example of this is East Tamaki but it can also be seen in many other employment areas such as Albany, Takapuna, East Tamaki and Manukau. Below is East Tamaki.
The opposite tends to be seen in what are primarily dormitory areas such as Sunnynook below. You can see residents there are primarily travelling to Albany/North Harbour, Wairau Rd-Takapuna or the Central City.
With both the employment areas and residential suburbs what you notice is that in addition to local workers, a lot of people are doing long distance trips across town. That highlights that even if local employment exists, many workers don’t work locally which is likely due to a wide range of factors.
In addition to the map the tables that make up the data for each area unit are also available by selecting the area unit you want and then clicking the tables link at the top of the page or in the chart to the right of the map.
I think it would be great to be able to group together various area units – such as the central city ones but overall a very neat and useful visualisation – one that I’m likely to use a lot. I also certainly hope that Stats NZ start doing more visualisations like this.