Photo by Eric Stuve.

[This is a variation of a piece that also runs in Time Out Chicago magazine.]

Q: When a highway sign tells us Chicago is a certain number of miles away, from what point in the city is it measuring: the outermost boundary line or from, say, State and Madison, the zero point of the street grid?

A: Good question. The first lines from the 1999 earworm “Someday We’ll Know” by New Radicals have always bugged us: “90 miles outside Chicago / Can’t stop driving / I don’t know why.” Is the singer talking about the distance to the city limits or downtown? Illinois Department of Transportation spokesman Josh Kauffman says it’s the latter. “Highway signage typically refers to the distance to the main business district of city,” he says. “So in Chicago that would be the center of Loop.”

Kauffman couldn’t pinpoint exactly what intersection IDOT considers to be Chicago’s epicenter, but Amy Krouse, spokeswoman for Skokie-based Rand McNally, says mileage between cities is usually calculated from one city hall to another. Accordingly, both Rand McNally’s online mapping service and Mapquest.com locate their Chicago pushpins at LaSalle and Randolph, spitting distance from Rahm’s office. Now we know exactly what Elwood Blues meant when he said, “It’s 106 miles to Chicago, we got a full tank of gas, half a pack of cigarettes, it’s dark… and we’re wearing sunglasses.”

Mileage measurements are important to bicycle touring: when you see a sign that your destination town is X miles away, you want to know if that’s to the city center or the edge of town, because every mile counts when you’re pedaling.