That's according to the Free Dictionary.
And if we accept that definition (as we do) the only thing keeping this most-excellent map from being a flowchart is sequence.
This beautiful translation of the Eisenhower Interstate System into "London Tube" map style was done by Flick'r member Senex Prime. You really need to click through to the large version to appreciate it's majesty.
It isn't a flowchart though. It's a map. If it had directionality built in, then it would qualify. It's really too bad, since there's no possible way I could post it on this blog unless it's a flowchart...
Perhaps if we say this map was designed to get me from Boston to San Francisco? We could overlay a few arrows, highlight one preferred route?
Whatever. One must accept life as it presents itself.
I wanted to share it here because it is such a beautiful design (based on the work of H. C. Beck, who did the London Underground map). It's visually pleasing and wholly useful. How many things can you say that about? Excellent work Senex Prime!
As Senex says on his Flick'r page:
"I have rendered the Interstate system in a much simpler form. I have made the "major" highways (those divisible by 5) the framework of the map, with the "minor" highways reduced in importance and rendered as thinner grey lines. Even with these highways, a difference in the greys indicates whether they are even-numbered (west-east) or odd-numbered (north-south). Dots on the highways indicate interchanges: large dots where major highways meet other major highways, smaller dots where major meets minor and tiny dots where minor highways begin or end. A full key at the bottom indicates clearly where each highway begins and ends."
Honestly, I can imagine traversing the country with nothing more than this map and I've driven back and forth three times.