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datamade / chicago-elections

API for local chicago election
http://chicagoelections.datamade.us/elections/22/
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Check whether precinct boundaries have changed #6

Closed evz closed 3 years ago

evz commented 11 years ago

Given the date range of elections that we have scraped, we'll want to check with the Chicago Board of Elections to see whether or not the precinct boundaries have changed.

fgregg commented 11 years ago

I asked if there were shapefiles available

Dear Mr. Gregg,

Yes, precinct boundaries change especially after a new census when re-districting of all voting districts occurs. Changes also occur to a smaller degree in the intervening years for a variety of reasons -- sometimes to adjust to shifts in population, sometimes to reflect the availability of a polling place or the ability to consolidate two or three precincts into one or two precincts, and sometimes to respond to issues raised by voters about the inability to access a precinct because of a major barrier, such as a large thoroughfare.

For these and other reasons, we do keep maps that were in effect for each election.

Regards, Jim Allen Communications Chicago Board of Elections jallen@chicagoelections.com

fgregg commented 11 years ago

Made a FOIA request for the DGN files they used between 2002 and 2012.

evz commented 11 years ago

Did a bit of research into this format last night and it would seem that it's some kind of CAD derivative which is supported by OGR as long as they are in a format older than version 8 (I have not idea what that means). The one caveat is that they don't actually contain any georeferencing information meaning that we'd have to project them on our own. That could be tricky but I think it's worth it to liberate the data.

fgregg commented 11 years ago

Here's what I sent yesterday

Dear Ms. Agnew,

This is a request under the Freedom of Information Act.

I request that a copy of the following information be provided to me: all versions of the election precinct boundaries from 2002 to 2012. I am requesting the boundaries in the forms of PDF maps and as DGN files. Thank you for your consideration of this request.

Sincerely, Forest Gregg

evz commented 11 years ago

Spoke with Corey Mollet who says he's encountered DGN files before and that, as I suspected, they can be kind of a pain because of the lack of spatial reference. He said that he'd love to compare notes when we get some files as it's a problem he's be trying to solve as well.