Whatever you say about the rest of the world, New Jersey is definitely not part of Manhattan... I'm surprised there isn't some kind of grey fuzzing-out on that part of the globe.
Why do the avenue lines meet at an antipode? In Manhattan, they are parallel, they don't converge.
I understand the difference between latitude and longitude lines. A meridian of longitude is a great circle centered at the Earth's center; a line of latitude is a small circle (the analogue of a chord in a 2D circle on a plane) whose center lies north or south of the Earth's center in three dimensions. Longitude lines divide a sphere like slices of an orange, converging at poles; latitude lines divide a sphere like a tomato slicer and do not converge.
There's actually two "poles"; aside from the one in Uzbekistan that everyone is seeing, there's another in the South Pacific Ocean at the antipodal point from Uzbekistan. So the avenues are being treated as meridian lines; great circles. Would it be more accurate to extrapolate avenues as parallel small circles?
We could test this theory by inspecting whether Manhattan's actual grid respects the curvature of the Earth. If the avenues are closer together at the northern end of the island, then the avenues actually do behave as meridians. If not, then the extrapolated avenue lines should be small circles and would not converge. You'd still have a pole in Uzbekistan, where the last street becomes an arbitrarily small circle, but just one avenue line through it. (I gotta run at the moment but will throw some trigonometry at this later.)
> Why do the avenue lines meet at an antipode? In Manhattan, they are parallel, they don't converge.
Sure they do. Manhattan isn't a plane; it's a region on the surface of a sphere. From Wikipedia[1], "In the spherical plane, all geodesics are great circles. ...all great circles intersect each other."
Clearly, it's the non-intersecting streets that are at fault here. They should intersect, but don't.
That the avenues converge is your assumption. The avenues may not be geodesics. They may be parallel small circles. Manhattan is of course a region on the surface of a sphere, but the avenues could behave either way.
Throwing together that promised trigonometry, with some approximations (using round numbers, ignoring the oblateness of the sphere, ignoring the skew of Manhattan's grid from due north-south):
40° = approx latitude of Manhattan's south end
40.27° = approx latitude of Manhattan's other end 30 km north
40000 km * cos(40°) = circumference of the 40° parallel
40000 km * cos(40.27°) = circumference of the 40.27° parallel
0.996 = ratio of the distance between avenues at the north end compared to the south
300 m = assumed approximate distance between avenues at the south end
298.8 m = expected distance between avenues at the north end
If the avenues are geodesics, they should be 1.2m closer to each other at the north end of Manhattan than the south end. Unfortunately a difference that small is probably essentially noise and below statistical significance to actually measure; the width of a sidewalk or a bicycle lane.
You're right about the avenues, but as for the streets I decided to make them concentric circles, completely analogous to lines of latitude. So they never intersect.
Haha interesting point about measuring the avenues to see which method is more accurate.
I was primarily inspired by lines of latitude (streets) and longitude (avenues), but I'd definitely be interested to see what it looks like when both are treated as concentric small circles.
The naming is a little off, isn't it? South of Houston all bets for street numbers are off, so I'm fine with making up South Xth street, but you should maintain the consistency the grid currently has.
You've lost the East/West distinction between the streets, so the West streets are just Xth Street, instead of West Xth Street like they should be. Worse, the avenues East of 1st should be named alphabetically, not as E Xth Ave. For consistency, I'd increment them as Ave A, Ave B, Ave C ... Ave Y, Ave Z, Ave AA, ... You've turned Alphabet City into just the East Avenues. Sacrilege.
I considered doing that, but I thought Ave AAA might just confuse people, especially people who don't know NYC. And I kind of like that I'm squashing all the nuances with this simple cruel grid :P
Yes this is definitely just Mercator. But you could reproject in a Manhattan-relative way, such that this larger grid actually looks like a grid (just like latitude and longitude do in Mercator) and that might be a... pointless new projection.
This doesn't make a lot of sense for Manhattan, because the grid doesn't have a center point; there's no numbering convention for streets south of Houston or avenues east of York/A. It would make more sense for cities like Miami or Salt Lake City, where there is a quadrant system and (for the most part) consistent spacing of streets
I don't think the grid is completely correct in Manhattan, even where the grid exists. It puts Washington Square Park , which southern end should be 4th street, as 6th street, and on the northern end of the grid, George Washington Bridge, which comes into Manhattan at 175th (I believe), is marked at 180/181st.
This is a really cool map, but some minor adjustments and testing to get the correct fit in Manhattan first would make a notable improvement in the overall product. I'd say fitting goals would be Houston as 1st street, and maybe 191st-200s area for north bound (Bronx continues the pattern, but it's much less consistent). Good work!
The Chicago grid actually does extend well into Indiana, and its numbering system makes slightly more sense. It'd be nice to have a version of this for the Second City.
Oh, why did you do it? Real estate developers in Bangalore have already started quoting higher prices by labeling the NY address to local properties :(
Manhattan - like most US cities have streets/avenues based on a regular grid and numbered consecutively Streets East/West and Avenues North/South.
So you can continue the numbering scheme across the entire world. The angles are due to the fact that the streets are aligned with the island of Manhattan rather than geographic north.
I live in a city with a street plan defined by an irrigation ditch cut around 1300AD and a market place that was active 1150 AD or so. Other places nearby have main streets surveyed originally by the Romans.
I suspect this was not a troll.
Greetings from very near 10137Ave, 62586st, bluenose territory.
The original main street in this city was pretty much defined by the 12,000 year old glaciated tail behind the crag of a 350 million year old volcano. :-)
