Image by versageek and licensed under Created Commons.










Through initiatives such as Vision Zero, D.C. and other cities across the United States are looking at different ways to use data in achieve zero fatalities and serious injuries to travelers of transportation systems by 2024. The District Ninja team is a big fan of this initiative.  As some of you will recall, we have published two different posts on the District’s Vision Zero initiatives and data for both pedestrians and bicyclists. With the recent D.C. Vision Zero Hackathon and the D.C. Department of Transportation’s release of considerable data, the District Ninja team decided a new Vision Zero related post was in order.

In the past year, 13% of drivers reported getting behind the wheel when they likely had a blood alcohol level that bordered or exceeded the legal limit. This appears to happen with some frequency, as approximately one in ten people reported having operated their car several times under such conditions in the past year. With such sobering statistics (pun somewhat intended), the team set out to see what the state of impaired-related vehicular crashes was in the District.

In order to get a better idea of trends over time, we defined the relevant time period as 2010 until 2014. We used the D.C. Department of Transportation’s vehicular crash data and the D.C. Office of Planning’s Neighborhood Cluster set in order to show where impaired crashes occurred.

Data Analysis

First we used R to geo-fence and aggregate our data to show Impaired Crashes from 2010 to 2014 broken down by neighborhood (and can be seen above). We leveraged D3JS and the various data sets mentioned above to find the follow:

  • 2011 and 2012 had same amount of impaired driving crashes at 170 for each year.
  • 853 Total Crashes
  • Golden Triangle has the most with 33 from 2010-2014
  • Neighborhood on the increase: Adams Morgan. Increased from 2012 to 2014.
  • Neighborhood on decline: Petworth. Decreased from 2012 to 2014 each year.

Next we created this torque map which shows you every crash in D.C. from 2010 to 2014 that involved an impaired driver when the crash occurred. There are two different bar charts to show the difference between crashes where the driver’s ability was classified as “ability impaired” vs. “had been drinking and obviously drunk.” You can click here in order to access the map in full screen mode. From 2013 to 2014, we can see that while figures appear to be increasing in both categories, the increases are hardly equal. For “Had been drinking and obviously drunk” there was a roughly 9% increase from 2013 to 2014. While “Ability Impaired” saw an increase of approximately 25%. We were also interested to see that both categories have never seen a decline from one year to another.

This next visual represents the top 10 D.C. neighborhoods that experienced the most amount of impairment-related vehicular crashes from 2010 to 2014. It looks like within the top 10 neighborhoods and likely all of D.C., no neighborhood saw more than 12 impairment related vehicular crashes in a year from 2010 to 2014. With 62 total, 2014 had the highest number of impairment related vehicular crashes within the top 10, roughly a 34% increase from the 46 crashes in 2010. When it comes to the largest up tick in total incidents from one year to the next, Cardozo/Shaw experienced a whopping 400% increase in total incidents from 2013 (3 total) to 2014 (12 total).

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