Thursday, May 18, 2017

Data Visualization Needs to Be in Scale

I saw this graphic on Twitter this morning, courtesy of Jennifer Keesmaat, chief planner for the city of Toronto:

Yes, it takes a lot longer to stop the faster you're going. So I thought, Wow, great graphic, I'll have to save that.

And then I thought, Wait a minute... the data is accurate but the image is completely inaccurate! Here's what it should look like:

I had to make it a lot wider to show the relative distances, and while I was at it, I added our retrograde American miles and feet translations.

In St. Paul and other towns and cities in Minnesota we are stuck with a 30 mph speed limit. We can't change it to even 25, let alone 20, which would obviously make pedestrians a lot safer (if drivers of cars obey the speed limit).

And that's not even getting into the difference in the force of impact at these various speeds; that also goes up exponentially.

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