M. V. Jantzen has designed a fun tool that let's you rearrange a subway map to show actual travel times from where you are. It's featured today at Greater Greater Washington. Here's Washington DC Metro viewed from Ballston station in Virginia:
Jantzen calls this a "distortion," and with that I would disagree. It's a redistortion, because as Mark Monmonier explains in his classic book, all useful maps are distorted. Here's a whole page of Washington Metro maps, including the classic diagram …
and a spatial one …
Spatial maps are about spatial distance, and that's often, but not always, what matters. The classic London Tube map is useful as a diagram, for example, but it can also undermine people's actual mental understanding of the geography of London.
Source: Transport for London
Of the above image, Kerwin Datu writes:
Bayswater and Queensway are 190 metres apart on the same street, Regent's Park and Great Portland Street 230 metres apart on the same street. But anyone going from Oxford Circus to either Bayswater or Great Portland Street would be persuaded that they had to take two trains to complete their trip. … This is unacceptable in a low-carbon age, and with trains packed to the gills in peak hour …
Back to the biggest picture point:
Maps that show one useful geography correctly seem so naturally authoritative that we can easily overvalue them when we really care about something else.
Consider the way spatial geography is misused — by almost all media — to represent population. If you think this is a useful map of the recent Iowa Republican caucuses …
… then you're misreading space as population. The visual impression of dominating such a map arises from appealing to sparse rural voters who influence large spaces on the map. Winning an election is something else. The guy who won the orange counties did as well as the guy who won the purple ones, because the orange counties are where most people live.
(Updated) Back in the 2004 election, some smarter cartographers attempted maps (technically cartograms) in which each bit of area represented a fixed number of voters. (Thanks to Niralisse for finding them for me!) The US was reshaped into something looking like an angry cat wearing a corset, the mountain states reduced to almost nothing while the West and Northeast were enormous blobs.
It took a while to get into, but it was an accurate visualization of what voters did. It was a useful redistortion, arguably a net reduction in distortion, because when describing population-based data, a spatial map like the Iowa caucus map above is a distortion too.
Inevitably, as technology customizes everything around our individual narcissism perspectives and preferences, we'll get more used to "just for me" maps, maps that show how the universe really does revolve around ourselves. These are crucial for their purpose. I've especially praised this one, which shows where you can get to on transit, in a given time, from a point that you select.
Ultimately, a clear vision of your city, your transit system, and your place in the world can only come from being able to move quickly between different kinds of maps, so that you're reminded at each moment that no map tells the whole story. We must be able to redistort for ourselves, in real time. If everyone had the tools to toggle quickly among different kinds of diagrams, they might even get over the notion that a spatial map tells you anything about an election.