Good magazine has a chart intended to make the point that public transit in US cities lags behind that of large cities elsewhere in the world. It's an awful chart. Any chart that takes a good three minutes of staring to figure out what it was trying to represent isn't doing its job. Let's count the ways it fails:
- It doesn't fit on the screen (or my screen, at least). It's impossible to compare the cities when you have to scroll around. I had to view the JPG -- a poor choice of format for any chart -- and use Firefox's image zoom feature to see it all in context.
- The length of the trains is clearly supposed to represent something, but what? It's none of the statistics listed on the yellow box on the right hand side, clearly. All of the trains extend off the left side of the chart, so I assume it's a scale that doesn't begin at zero. New York's train doesn't fit on the chart at all. It takes some searching, but a tiny legend at the bottom-right reveals that it represents total system track length. Why this is a more important measure to devote to charting than, say, city population is beyond me. "System Track Length" itself is a vague concept: Paris's chart clearly doesn't include the 365 miles of the RER, for example.
- London's Tube, one of the oldest, largest, and most-ridden subway systems isn't included. How were the included cities chosen? The title says "The most used subway systems in the US and the World". The selected cities suggest otherwise.
- The city statistics in the yellow boxes on the right don't line up with the corresponding chart elements for the city.
- Using the people to represent the number of riders (actually millions of rides per day -- that legend is a bit easier to find) is overly cute. Also for some reason Chicago's riders are packed in tightly, but there are many unexplained gaps between Tokyo's riders. I assume this is not meant to be meaningful.