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Azavea - Do Good Data 2015

Azavea - Do Good Data 2015

A presentation at Do Good Data 2015 by Tyler Dahlberg and Daniel McGlone on behalf of Azavea. About bicyle theft, pedestrian-auto crashes, case studies, and GIS analysis and webmapping.

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Tyler Dahlberg

May 01, 2015
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  1. bit.ly/DGDGIS 1. Case Study - Bicycle Coalition 2. Case Study

    - PlanPhilly 3. Demo - QGIS 4. Demo - CartoDB 5. Recommended tools
  2. B Corporation • Civic / Social Apps • Pro Bono

    Program • Donate share of profits Research-Driven • 10% Academic Research Program • Academic Collaborators • Open Source • Open Data
  3. More at Summerofmaps.com • $5,000 Fellowship for Student GIS Analysts

    • Work on pro-bono projects for nonprofits • Mentored by Azavea Staff
  4. What about Chicago? • http://data.cityofchicago.org • Only 4,652 in twice

    the length of time? • May be due to CPD’s insistence on serial #s
  5. How did we analyze bike theft? 1. Georeferenced and cleaned

    the data 2. Looked for social trends 3. Looked for spatial trends 4. Looked for temporal trends
  6. Georeferencing A few ways to get things on a map:

    1. “Geocode” address data: 123 Main St, Lake Mills, IA, 50450 2. Georeference: pushing pins on a map 3. Use spatial data: Shapefiles, anything with lat-long
  7. Cleaning the data • All records had latitude-longitude • Looked

    for outliers by value • Looked for outliers in space
  8. Spatial Regressions • Which social factors correlate with bike theft?

    • Hard to say because extremely high spatial clustering broke the models
  9. PlanPhilly Political twist for impact: • Overlay council districts, find

    the crash hotspots in each district • Tie into the growing Vision Zero movement and newly created urbanist PAC to influence city elections
  10. Where does crash data come from? • It’s usually not

    open data • Reported by police in local jurisdictions, data maintained by State DOTs
  11. Hotspot Analysis • Known as the Getis-Ord GI* • ArcGIS

    tool in ArcMap 10.1 and later • Identifies spatially significant clusters of “high” and “low” values OR • Aggregates incident data into geographic bins for analysis
  12. What are we missing? • Pedestrian counts -- to create

    crash rate • Better way to aggregate crash data for hotspot analysis: Intersection Polygons
  13. Impact PlanPhilly using this work to motivate community to demand

    safer, better designed streets and intersections
  14. Conclusion • “Spatial” opens new avenues for analysis • If

    you have an address or a latitude/longitude coordinate, you have spatial data • Maps are relatable and give context