# Transit maps TED talk!

I suppose it’s possible that you don’t share my passion for transit maps. That might be hard to believe, but I admit that it’s possible. Whether you love transit maps or not, you still need to watch Aris Ventikidis’s first-rate (and short!) TED talk on that subject, focusing on a new public transit map for Dublin. (Dublin? “Ventikidis”? Don’t worry, he explains all that — how his family moved from Turkey to Greece to Germany to Ireland, a path that helped shape his current worldview.)

Transit maps are, of course, fascinating as graphic design, as geography, and as mathematics. Consider, for instance, two unofficial maps of the MBTA here in the Boston area:

From a mathematical point of view, these are both representations of the same object (just as a graph, an algebraic rule, a table, and a computer program might all be representations of the same function), but they serve very different purposes (as do the function representations). You’ll notice that the map on the left consists of straight line segments, joined by angles that are multiples of 45°. You’ll also notice that the subway “lines” in the map on the right go every which way, making it a poorer match to the mental map we have of subway lines. The map on the left is a topological map, making it easy to see how to get from one station to another. The map on the right is a scale map, showing the true geographical relationships and distances between stations. Each has its purpose…but in math we too often insist on scale representations of everything. Anyway, the TED talk by Ventikidis provides a great explanation of all this (without the mathematics), in the context of the truly confusing public transit situation in Dublin. He tries to improve both the actual transit and the map of it, starting with his drawing of how it was and ending with his drawing of how it should be:

For a full explanation, watch the TED talk and read Eric Jaffe’s essay.

Categories: Dorchester/Boston, Math, Model Railroading, Travel