In news reports, information is often given on a location in relation to a major city. Such as - The shooting occurred at The Oaks mall in the city of Thousand Oaks, about 40 miles (64 kilometers) west of Los Angeles.
Is this measured from the center of LA or the city boundary ?
Thanks
They probably just ask some map program for the distance between <event location> and <city>, which would give them whatever point the map program considers to be the city center.
It’s obviously not the city boundary, because Woodland Hills, which is technically in the City of Los Angeles, is only about 20 miles from Thousand Oaks, and would be the closest city boundary.
From what I’ve noticed, it’s the civic center, as Chronos says, but they usually just use a round figure.
In Australian Capital cities, it was traditionally and typically the central post office. In Perth, there is a specifically a plaque near the post office which directly states it is the point to which all official measurements are based on with relation to distance from Perth. Now the more common tools are Google maps and such, and I’m not sure if they follow this convention or use some other geodesic reference point based on city boundaries.
Using Google Maps to get directions, and using “Los Angeles, California, USA” as a destination, I found that (for Google) Los Angeles is located close to the corner of W 1st Street, E 1st Street, N Main Street and S Main Street. Since that’s where (for street-naming purposes) East meets West and North meets South, that would be a logical place for the centre of Los Angeles.
I’ve always wondered this too, because if you measure from a point to a city center, it’s a different figure than if measured to the city limits. For large cities, a large difference. Why would they say you’re 10 miles from Cityville if after going only 4 or 5 miles you’re already in Cityville?
If you try a few, they don’t seem to follow a consistent pattern, even in one source. For instance, on Google Maps, Cupertino, CA gives me the corner of Stevens Creek and DeAnza - OK, a major intersection. Denver puts me in front of Civic Center Park. Missoula, MT, the corner of Broadway & Higgins, a major intersection again. San Francisco, Market and Van Ness. Sacramento, Cesar Chavez Plaza. They seem to be divided between some notable location, not necessarily a civic building, and a major “downtown” intersection. Although, Portland, OR seems to be neither. It’s the corner of 6th and Burnside. Maybe somebody from Portland could tell me what that is. The geographic center?
It doesn’t work that way in all cities, though. For Chicago, the “center” of the grid system is the corner of State & Madison; but Google Maps uses a spot about four blocks away as the default starting spot for “Chicago”.
The default spot for “New York” appears to be New York City Hall, which makes a certain amount of sense.
I’ve been told that’s it’s the main post office, but I don’t have a cite yet.
Yeah, and Mapquest (remember that? Apparently still around), Bing, and Apple maps all put you on LaSalle near City Hall. Waze gives you the same location as Google Maps. (I guess there’s the federal building right there, but, otherwise, nothing of note like City Hall that would make sense to me as the center of Chicago.) That said, like you said, State & Madison is where every schoolkid knows the grid starts, so classically would be considered the center of the city by many. There’s also the geographic center (at least by one definition), which is a bit less known, that is in the Heart of Chicago neighborhood on the south/near Southwest side (there is or was a big sign on 37th and Honore trumpeting that.)
Local esoterica aside, when I worked in journalism, I don’t remember there being any standardized method of defining these sorts of distances. I presume reporters just type in the two locations in a map program, see the distance, and then use their judgment to convey the approximate distance. In your example, “about 40 miles” covers both measuring from downtown and from the border. It’s all well within what I’d consider the level of granularity I would expect from that distance. Now, if something took place, say, a mile from the city border but 6 miles from downtown, I would expect the writer to clarify by saying “six miles from downtown” or “a mile from the city limits.”
Also, how often that a local reporter just ‘knows’ the approximate distance and all the other stations just run with that number. In many instances, people don’t really care if it’s 40 or 50 miles, they just want to know if this city they’ve never heard of is 40 or 2500 miles from some place they have heard of.
For example, I’m about 90 miles North of Chicago. Maybe it’s 80, maybe it’s a hundred, but if something happened here, “90 miles North of Chicago” is all someone that lives thousands of miles away is concerned about. It just helps people put it in perspective.
Burnside is the street that divides “north” and “south” in the cartographic sense. There’s NW/SW 6th and NE/SE 6th, on either side of the Willamette River, and neither has anything remarkable at its intersection with Burnside. The Willamette divides “west” and “east,” maybe Google doesn’t want to give coordinates in the middle of the Burnside Bridge? I got nothin’.
In Budapest it is the zero-kilometer stone marker located on the Buda side near the bottom of the funicular.
For Cleveland, the logical point would be the center of Public Square, but it looks like Google Maps uses a point on the western edge of the Square (possibly because the interior of Public Square is now closed to cars). They used to use a completely unremarkable point a couple of blocks north and three blocks west, which I’m guessing was the result of someone sticking a metaphorical pin into the map, at a fairly wide (i.e., imprecise) zoom level.
Growing up in Australia, i was always taught that it was the post office too. My mother, who grew up in England, said the same this, but it seems that it might not actually be true for the UK. In London, for example, there’s actually a marker in Trafalgar Square showing the exact spot; you can see it in this BBC article.
It seems to be a bit different with the mapping software. For example, if you ask Google maps to take you to Sydney (from, say, Goulburn), it places the destination at the MLC building on King Street. That’s about one block south and two blocks east of the old post office building on Martin Place. That’s fine, i guess, but i think that the GPO would be a better target than a rather nondescript commercial building like the MLC. Even better might be Town Hall, on George Street.
The BBC article i linked above notes that there is no universal rule for the modern mapping systems, and also notes that:
The story also notes that sometimes the marker is simply the historic location of a statue that no longer exists, like an old market cross or similar feature.
GIS calculates the centroid of all polygons in a system by default. Now, I’m not sure if the various different routing applications have the polygons that define a cities/towns boundary, but that’s what I would use. Using the City Governments ‘building’ doesn’t really work as there are often many of them, and ‘main’ one that the Mayor has an office at, could very well be at the edge of the city. And it would take more input from someone to determine just what location to use.
A polygon centroid might not always be the best choice. Imagine, for instance, a coastal city in the shape of a semicircle (the other half of the circle, of course, being out over the water). The logical center of such a city is the center of the circle, but the centroid is going to be somewhere further inland.
Yep, that was going to be exactly my argument. If someone driving to Southern California wants to know the distance to San Diego, the centroid would probably put them somewhere north of Kearny Mesa, around the Miramar military base. That’s not what most drivers would expect.
Right. As an ex-taxi driver in L.A., I thought about that. We had to very familiar with the intersection of 1st and Main, because that’s “ground zero” for the address numbering system of streets, which can be E., W., N. or S. from there.
But as MikeS says, some cities may not have such a point, or Google chooses something different.
My question for journalists, however, is this: If you use an online map system, do you just use the driving distance, or the the geodesic distance? The location of the shooting in the OP is actually 38 miles from 1st and Main in L.A. in terms of geodesic distance, but 43 miles driving.
Google hasn’t made their criteria public, so I expect it’s more complicated than simply choosing a center point. If they were doing something as simple as the geographical center or post office, they wouldn’t have much reason to be secretive.
I expect it’s something along the lines of a calculated center based on users final destinations. They wouldn’t want to make the method known because people could manipulate the calculation. It isn’t changing on a daily basis but for some towns I’ve gotten different centers over the years.