8 ms·
I have a question about the allocation of blocks and the definition of "inhabited". Firstly, from the numbers given, it seems that the average size of a block
by mannykannot 6y ago
I have a question about the allocation of blocks and the definition of "inhabited".
Firstly, from the numbers given, it seems that the average size of a block is a little less than a square kilometer.
In some places, major highways show up as thin ribbons in the high-resolution display [1]. One example that I am familiar with is Interstate 84 across the Poconos in North-Eastern Pennsylvania. I located one section of this highway in Google maps [1]. Using the distance-mearsuring tool to mark out a square kilometer, it was clear that, if these blocks were square kilometers, or some other compact shape of that area, the highway would not appear as thin as it does, and one would not be able to pick out the wiggles in the highway's route, which actually show up in considerable detail.
Maybe these roads (and also streams, which show even more detail) are additional features on the map, unfortunately also colored green, but if so, the selection of which ones to show seems rather arbitrary.
Regardless, there are also several sections where it seems implausible that there is any dwelling within a kilometer's distance of the highway - for example, either side of I-84 at [2], yet, on the census map, the highway threads through here as a thin green line on a white background ([3]; south-east quadrant.)
At the very least, it seems unlikely that the blocks are arranged as a uniform square grid.
[1] https://mapsbynik.com/maps/census0pop/ https://mapsbynik.com/maps/census0pop/
[2] https://www.google.com/maps/place/41%C2%B020'59.2%22N+74%C2%B056'47.7%22W https://www.google.com/maps/place/41%C2%B020'59.2%22N+74%C2%...
[3] http://mapsbynik.com/maps/census0pop/tiles-140420/TileGroup150/9-376-44.jpg http://mapsbynik.com/maps/census0pop/tiles-140420/TileGroup1...
- jcrawfordor 6y agoCensus blocks are intentionally bounded by geographical features such as roads and are not intended to be of uniform size. Census blocks are intended as an organizational unit for census data and not necessarily for any comparative use, such as this website makes, since it's clear that the demographics of blocks will vary widely depending on location, size, etc. Historically census blocks were determined in the field as an early stage of enumeration based on local conventions, but today they're defined semi-automatically from GIS data. Still, what exactly defines a block and what is typical of them varies widely from place to place. Blocks are the lowest level of the hierarchy in which census data is organized, next being block groups and then tracts.