[Data Viz] Crayon the Grid
We were digging around some data blogs and found this post from back in October.
Have you ever noticed that some cities are just easier to navigate when you’re driving? It might be but it might be how the city was designed. Are there a lot of traffic rotaries or one-way streets? Does the city cascade out from its center like Paris or London, or is it a system of grids? For the latter question, Data Visualization expert Stephen Von Worley put together images of 9 different cities, color-coded by alignment so that you can see how the city is “organized”.
This is how he did it:
For the detail-oriented, these are 100%-algorithmic images generated from MapZen’sMigurski-inspired October 2014 OpenStreetMap Metro Extracts as follows. First, we assign each linear street segment a compass-heading-based tone from a modified sinebow, where a 90 degree directional difference corresponds to a full color revolution, so that roads at right angles to each other have the same hue. Then, to render each point on the map, we use Proximatic, my custom high-performance k-NN engine, to calculate the length-weighted average of the colors assigned to the nearest 500 meters of street, keying render weight to the local degree of parallelism/orthogonality (derived in a similar mod-90° vector space), with rolloffs for outlying roads and territory.
There definitely seems to be an impact on traffic based on the design of a city. Take London- a radial explosion of beautiful, colorful chaos. Historically, the Romans (and whomever else) did not build London imagining that, someday, it would house around 3 million drivers. Check out our recent spotlight on London: note that many of the “worst days to drive” were during major events or holidays that featured immense concentrations of people in the metropolitan area.
For example, Halloween 2014 in London turned a 30km drive (30 minutes at 60 km/h or 37 mp/h) into an hour and a half. Compare this to somewhere like New York City (where Halloween is also big deal) which has more than three times the amount of licensed drivers as London. Despite a major holiday on Friday, drive times were still average at 43 minutes ands speeds even hit a weekly high at 39 km/h.
Perhaps New York City has a better driving infrastructure than London. Maybe the locations of the events don’t intersect with as many major thoroughfares and byways. Either way, when you look at the stark visual difference between the infinitesimal starbursts of color in London or Paris, compared to the delicate window-screen latticework of New York, Chicago, or even San Francisco- it’s hard not to see a correlation.
Make sure to click through above to see all 9 cities- you can even zoom and pan through the maps.