Thread by @BarbChamberlain

Before you RT this catchy infographic, a thread--
#RoadSafety #VisionZero #dataviz

External Tweet loading...
If nothing shows, it may have been deleted
by @NewUrbanism view original on Twitter

Infographics work. I clicked. My first response: Catchy title but the piece provides zero basis for the statement. Data-driven safety improvements are essential--so where's the data? This could have been so much more. #RoadSafety #visionzero

Dug a bit. Googled law firm credited on map. Got thedrive.com/sheetmetal/144… telling me it's @NHTSA "accident" (sic) data for "automobiles/pedestrians". Where are bicycles/motorcycles? More Google. #CrashNotAccident #RoadSafety #VisionZero

That piece linked to short @TIME piece time.com/this-is-americ… telling me their analysis was fatalities. So maybe all road users, not just auto/ped. But wait, there's more. #RoadSafety #VisionZero #dataviz

Top Google results all refer to @NHTSA data. Scroll down to infographicjournal.com/the-most-dange…: "Using crowd sourced data from Badintersections.com and 9 years of data from the National Highway Traffic Safety Administration...based on automobile and pedestrian accident occurrences."

So we now have a map w/unspecified crowdsourced data of unknown quantity/quality for all road user types (per @badintersection statement on their site) + @NHTSA data that may be auto/ped only. #RoadSafety #VisionZero #dataviz

And don't forget, we also have a splashy infographic that got tons of media pickup. Big words! Turned sideways! So authoritative. #RoadSafety #VisionZero #dataviz

Don't get me wrong--As someone who works w/real crash data & wants to do real work to improve conditions for people on our streets/roads, I do want attention-getting tactics that focus attention. #RoadSafety #VisionZero #dataviz

But this is not helpful. To see it written up yet again w/no discussion of underlying source material, none of what I found in about 7 min w/Google that calls it into question.... #RoadSafety #VisionZero #dataviz

And it gets better, although I won't go down every rabbithole. Other sites (+ law firms) took the original list, mashed it up w/other sources of various vintages & origins, & created new "worst of" lists that then got reported as news. #RoadSafety #VisionZero #dataviz

Wait, maybe I WILL follow this a bit further. The original @TIME analysis (@NHTSA data only) listed worst intersection in US in Bensalem PA: time.com/this-is-americ… #RoadSafety #VisionZero #dataviz

But somehow Hawaii decides THEY have the worst intersection in US hawaiinewsnow.com/story/36682785…. (Sidebar complaint about media sites that don't date their posts.) #RoadSafety #VisionZero

Someone "dug into the numbers" (weak on methodology here) to produce their own list cheatsheet.com/money-career/l… which is, of course, presented as a countdown to #1. Their data source? Wait for it-- #RoadSafety #VisionZero

Turns out THAT Hawaii intersection collision data source is a map compiled by a law firm: davislevin.com/practice-area/… that appears to be based on govt data (link at bottom to data.honolulu.gov). #RoadSafety #VisionZero

But we don't know what data they pulled from that source. Fatalities only? That was what @TIME started with. For which modes? What time span? What locations? (Because the place identified isn't one intersection, it's now a bunch near a shopping mall.) #RoadSafety #VisionZero

Let me explain. No, let me sum up. @TIME uses @NHTSA data -> Law firm adds crowdsourced -> Someone "digs into numbers" using law firms & local media reports from all over as their sources -> Gets reported as news w/completely different results. #RoadSafety #VisionZero

So now if a public agency presents safety data bounded by specific sources, definitions, time frames, federal standards THIS is the climate in which they do so. "You're wrong! I just read a list of the worst intersections in America!" #RoadSafety #VisionZero

I stopped pulling on the threads but I'm sure they unravel further. All of this is to say that if you're looking at something that purports to be based on data, ask some questions. Don't let the type turned sideways turn your head, too. #RoadSafety #VisionZero

please unroll.