
Mapping Traffic Fatalities - sndean
http://lucaspuente.github.io/notes/2016/09/01/Mapping_Traffic_Fatalities
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niftich
I'm very pleased (from a data insight standpoint) that the map doesn't look
like a population heatmap [1].

As a next step, I suggest calculating the actual rate of fatalities in a
particular location vs. some naive estimate for that area, based on traffic
counts, car utilization, or nearby population. This will highlight places that
have a higher-than-expected number of fatalities.

Some of these places can already be seen visually. For example, Florida is
blotted in red even though the population is concentrated around the coasts
and bays and the Orlando area; therefore US 301 and other 'interior' portions
are more dangerous than population alone would explain.

The Carolinas are similarly covered, well-outside of the Crescent from
Raleigh-Durham through the Triad to the Charlotte suburbs. California's
Central Valley looks particularly dangerous too, despite most of the traffic
sticking to the far western edge with I-5, or the eastern valley floor where
the built-up areas are.

[1] [https://xkcd.com/1138/](https://xkcd.com/1138/)

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dandermotj
It looks exactly like a population heatmap.

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dx034
More like a traffic heatmap. California seems to have a lot of red dots on the
I5 between LA and SF. Not a lot of people live there.

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13of40
I wonder how much "proximity to a good hospital" changes it, as well. If I
could zoom in far enough, and traffic can be assumed to be constant, would
there be more fatalities on the remote parts of I-5?

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thr0waway1239
Would it help to use data like yearly per capita consumption of gasoline by
state [1] (as a proxy for miles driven per person) in addition to the existing
data? Would that make a difference and shed any more insight?

[1] [http://www.statemaster.com/graph/ene_gas_con_percap-
energy-g...](http://www.statemaster.com/graph/ene_gas_con_percap-energy-
gasoline-consumption-per-capita)

~~~
yaakov34
You can get vehicle miles driven by state directly, and also such data as
fatalities per road user and per miles driven:
[http://www.iihs.org/iihs/topics/t/general-
statistics/fatalit...](http://www.iihs.org/iihs/topics/t/general-
statistics/fatalityfacts/state-by-state-overview)

However, you won't get much insight from plotting this data geographically: a
table (as in that link) is enough. Basically you get exactly what is expected:
Daniel Patrick Moynihan's "Law of the Canadian Border" \- southern states have
more social problems.

If you want high-resolution geographical data for purposes such as finding
problem roads, that would be a lot more difficult - you need to have a graph
of the road network (from e.g. Open Street Map), with traffic data attached to
the arcs of the network (I don't know of any public access databases like
that, although such data is commercially available for road planning) plus
accident locations accurately mapped to the roads. I suspect it wouldn't be a
quick project to do.

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Agustus
I am struggling with what will be the purpose of this. Any project that I work
on with traffic analysis, PD&E, or roadway design includes a crash analysis.

The crash analysis includes an analysis of every accident within a five year
period, identification of high crash locations and what caused the crash (high
speed, inebriation, or a list of other options), and then what strategies can
be adopted for the most impact in a benefit/cost analysis.

Just looking at heat maps of crashes without inclusion of traffic volumes (one
crash per million miles is nothing compared to an area of one crash per
thousand miles traveled) becomes meaningless.

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danso
have a love-hate relationship with the NHTSA database. On one hand, it covers
40 years of data, and unlike virtually every other long-running dataset in
existence, it keeps not only a relatively standardized schema, it publishes a
all-in-one user manual that covers every year (and any changes between them);
most places publish a new PDF for every year, which means you have to read
through each one. Even better is that when they make changes or additions to
their methodology, they publish an auxiliary dataset that you can use to
retroactively update old datasets.

But then for some reason, they throw out all rationality when it comes to
naming files and fields. It's as if there was employee who was old-school and
was stuck in mindset of naming things under the 8-character all-caps
limitation. And then someone else thought, " _Fuck this_ ", and went the
entirely opposite direction by naming files with long titles and spaces, and
the two employees had a passive-aggressive argument that never got resolved
over the decades.

This makes scraping and collating the data a real pain in the ass. But
compiling the data got a lot easier when I realized that wget works on FTP
sites. Here's a mirror of the FTP site (around 1.7GB zipped) that I put up on
Github (still working on getting everything together in one database):
[https://github.com/wgetsnaps/ftp.nhtsa.dot.gov--
fars](https://github.com/wgetsnaps/ftp.nhtsa.dot.gov--fars)

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mikhailfranco
Already available for the UK, see:

[http://www.crashmap.co.uk/](http://www.crashmap.co.uk/)

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coldcode
Is it possible to make such a map for homicides? Does the data exist with
sufficient location information?

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danso
The FBI Uniform Crime Report and/or NIBRS may be the most
comprehensive/granular data there is on homicides nationwide, but I don't
think there's incident-level geography:

[https://www.icpsr.umich.edu/icpsrweb/NACJD/NIBRS/](https://www.icpsr.umich.edu/icpsrweb/NACJD/NIBRS/)

Counting homicides, and even determining what exactly is a homicide, is not as
clear as one might think:

[http://contentsmagazine.com/articles/homicide-watch-an-
inter...](http://contentsmagazine.com/articles/homicide-watch-an-interview/)

Not that many agencies post the data themselves. Surprisingly, the NYPD does
post it as part of their felonies dataset:
[https://data.cityofnewyork.us/Public-Safety/NYPD-7-Major-
Fel...](https://data.cityofnewyork.us/Public-Safety/NYPD-7-Major-Felony-
Incidents/hyij-8hr7/data)

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TillE
Good find with the NYPD link. I've seen New York data before that just went
precinct by precinct, but this has exact latitude and longitude.

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laurent123456
Isn't it pretty much a US population density map (if it's not, I can't quite
see the difference)? If there are differences, it would have been interesting
to display the number of accidents in an area as a proportion of the
population.

