Here's a completely anecdotal, "a friend of a friend.." story, but I think it's a cool yi and you'll enjoy it:
A friend of a friend is a cartographer who works in DC. According to this person, the official subway map of DC distorts the true geography of the city -- and the subway lines -- as much for security purposes as it does graphic design purposes. The red line, in particular, apparently is drawn with a completely bogus path through the city on the maps. The true path of the line goes underneath the national mall and several important government buildings, if this person is to be believed.
Subway "maps" tend to be more like generalized graph diagrams than cartographically accurate maps. After all, you're stuck in a box and your only choice is which node to get off at.
But it wouldn't surprise me if an overlay on a cartographic map was intentionally inaccurate. One time I was in DC a cab driver was trying to get me to my hotel. His GPS went totally nonfunctional when we were in view of the Pentagon.
It would be an interesting research project to ride around subway systems with a data-logging accelerometer (like a smartphone). Integrate acceleration to get velocity, integrate velocity to get relative position, get GPS fixes when the signal is available, and diagram the results.
Integrate acceleration to get velocity, integrate velocity to get relative position, get GPS fixes when the signal is available, and diagram the results.
Sadly integrating "real data" even once results in wild inaccuracies. A small error in acceleration turns into an offset in velocity which turns into large position drift over time.
Interesting, I had someone report something similar next to the Canadian SIS building in Ottawa. His GPS was telling him the completely wrong route. I don't have a GPS personally to try it.
His GPS went totally nonfunctional when we were in view of the Pentagon.
Which is pretty humorous since, once you're vaguely close to it, it's hard not to find it. If they built several other pentagonal buildings in the area, it would be a different story. :-)
Underground maps usually don't match the real geography. If you made a "real" map, it would be next to useless since the central stations should be all in one place with lots of empty space around. It's the destination / via station you care about when you know the destination, not realistic detail of the path itself.
http://en.wikipedia.org/wiki/Tube_map has some examples of more realistic London underground maps (older editions). It's a common topic of graphic design / visualisation courses.
The red line does turn south a bit going west out of Gallery Place, but it doesn't go any further south than D street and doesn't go under any important federal buildings.
Besides, what would be the point? The National Mall is absolutely riddled with tunnels! West to east there's an old streetcar tunnel at 14th Street under the Bureau of Engraving, the 12th and 9th street road tunnels open to trucks, two tunnels apiece for the yellow/green and orange/blue lines with the latter going under dozens of federal buildings, the entire Smithsonian subway station, large underground art galleries south of the Smithsonian castle, the buried watercourses of Tiber Creek, the National Gallery gift shop & cafeteria under 4th street, the I-395 Center Leg Freeway that has the DOL built on top of it, the United States Capitol subway system, the old C Street streetcar tunnel under Senate Park, and the First Street heavy rail tunnel under the LOC / Supreme Court.
Which official map - the one posted in each station and online? Sure it's distorted: it has to make sense to millions of tourists. Most transit maps I've seen are the same: geographic realism is sacrificed to make it easier for patrons to get around.
Orange and Blue lines go under the Mall: this is reflected on the map. IIRC there is one stop at the Mall, several close. There aren't any Red line stops near the Mall.
several important government buildings
It's D.C. You can't shake a stick without hitting an important government building.
Comments
Here's a completely anecdotal, "a friend of a friend.." story, but I think it's a cool yi and you'll enjoy it:
A friend of a friend is a cartographer who works in DC. According to this person, the official subway map of DC distorts the true geography of the city -- and the subway lines -- as much for security purposes as it does graphic design purposes. The red line, in particular, apparently is drawn with a completely bogus path through the city on the maps. The true path of the line goes underneath the national mall and several important government buildings, if this person is to be believed.
Subway "maps" tend to be more like generalized graph diagrams than cartographically accurate maps. After all, you're stuck in a box and your only choice is which node to get off at.
But it wouldn't surprise me if an overlay on a cartographic map was intentionally inaccurate. One time I was in DC a cab driver was trying to get me to my hotel. His GPS went totally nonfunctional when we were in view of the Pentagon.
It would be an interesting research project to ride around subway systems with a data-logging accelerometer (like a smartphone). Integrate acceleration to get velocity, integrate velocity to get relative position, get GPS fixes when the signal is available, and diagram the results.
Integrate acceleration to get velocity, integrate velocity to get relative position, get GPS fixes when the signal is available, and diagram the results. Sadly integrating "real data" even once results in wild inaccuracies. A small error in acceleration turns into an offset in velocity which turns into large position drift over time.
Interesting, I had someone report something similar next to the Canadian SIS building in Ottawa. His GPS was telling him the completely wrong route. I don't have a GPS personally to try it.
His GPS went totally nonfunctional when we were in view of the Pentagon.
Which is pretty humorous since, once you're vaguely close to it, it's hard not to find it. If they built several other pentagonal buildings in the area, it would be a different story. :-)
They might have some local GPS jammers to make it harder for unmanned drones or bombs to navigate near the building.
Underground maps usually don't match the real geography. If you made a "real" map, it would be next to useless since the central stations should be all in one place with lots of empty space around. It's the destination / via station you care about when you know the destination, not realistic detail of the path itself.
http://en.wikipedia.org/wiki/Tube_map has some examples of more realistic London underground maps (older editions). It's a common topic of graphic design / visualisation courses.
I'm a DC native and that story is bullshit.
The red line does turn south a bit going west out of Gallery Place, but it doesn't go any further south than D street and doesn't go under any important federal buildings.
Besides, what would be the point? The National Mall is absolutely riddled with tunnels! West to east there's an old streetcar tunnel at 14th Street under the Bureau of Engraving, the 12th and 9th street road tunnels open to trucks, two tunnels apiece for the yellow/green and orange/blue lines with the latter going under dozens of federal buildings, the entire Smithsonian subway station, large underground art galleries south of the Smithsonian castle, the buried watercourses of Tiber Creek, the National Gallery gift shop & cafeteria under 4th street, the I-395 Center Leg Freeway that has the DOL built on top of it, the United States Capitol subway system, the old C Street streetcar tunnel under Senate Park, and the First Street heavy rail tunnel under the LOC / Supreme Court.
Which official map - the one posted in each station and online? Sure it's distorted: it has to make sense to millions of tourists. Most transit maps I've seen are the same: geographic realism is sacrificed to make it easier for patrons to get around.
Orange and Blue lines go under the Mall: this is reflected on the map. IIRC there is one stop at the Mall, several close. There aren't any Red line stops near the Mall.
several important government buildings
It's D.C. You can't shake a stick without hitting an important government building.