My latest London data visualisation crunches an interesting dataset from the Department of Transport (there’s also a London Borough of Southwark version using their local observation data). The data is available across England, although I’ve chosen London in particular because of its more interesting (i.e. not just car dominated) traffic mix. I’ve also focused on just the data for 8am to 9am, to examine the height of the morning rush hour, when the roads are most heavily used. 15 years worth of data is included – although many recording stations don’t have data for each of those years. You can choose up to three modes of transport at once, with the three showing as three circles of different colours (red, yellow and blue) superimposed on each other. The size of each circle is proportional to the flow.
It’s not strictly a new visualisation, rather, it’s an updated version of an older one which had data from just one year, using “smoothed” counts. But it turns out that the raw counts, while by their nature more “noisy”, cover a great many more years and are split by hours of the day. I’ve also filtered out counting stations which haven’t had measurements made in the last few years.
Note also the graph colours and map colours don’t line up – unfortunately the Google Material API, that I am using for the charting, does not yet allow changing of colours.
An alternate mode for the map, using the second line of options, allows you to quantify the change between two years, for a single selected type of transport. Green circles show an increase between the first and second year, with purple indicating decreases.