Tag: ArcGIS

Measure A fails, and mapping

Dan Allison3 Comments

Measure A, the transportation sales tax for Sacramento County, failed spectacularly, 44% yes and 55% no. Advocates for a better, safer, more equitable transportation, and better investment of our transportation dollars, celebrate this failure. Final election results were released on December 8, 2022.

Sacramento County Measure A 2022 results

More analysis of the results and significance to come, but for now, some maps.

Sacramento County Elections provided a map of the Measure A results.

Sacramento County Elections, Measure A 2022 map

Sacramento Bee provided a similar though not identical map.

SacBee Measure A 2022 map

Both these maps indicate whether a precinct voted yes or no, but no indication of the number of voters or the proportion of the vote yes or no. There is a movement towards better election reporting maps, called ‘Land Doesn’t Vote, People Vote’. A few references are U.S. election maps are wildly misleading, so this designer fixed them, Election graphics 2020: Land (still) doesn’t vote, and Land Doesn’t Vote, People Do: This Electoral Map Tells the Real Story, but you can find many more.

Below is my first attempt at producing a better map for Measure A. Click on the graphic for a linked pdf, which allows you to zoom in on specific areas. What’s different? I used a range of colors, from red (no) to green (yes) votes (ArcGIS: graduated colors, equal interval, 10 classes). You can see there is much more subtle detail. There were a few precincts which voted entirely no or entirely yes, but very few. Most were somewhere in between. For elections (other than the antique federal electoral college), votes count, precincts do not.

The map still over-emphasizes precincts with large area and few voters (some precincts have as few as one person who actually voted). If you look (unfocus your eyes), you would think that there were almost no ‘yes’ votes in the county, but that is not accurate.

The data I used, modified from the Sacramento County Elections data, is here.

Measure A 2022 mp by Dan Allison, graduated colors

Some of the other map alternatives, which are better, require ArcGIS techniques and skills that I’m just looking into, so I expect I’ll have better maps soon. Stay tuned!

pedestrian collisions in Sacramento

Dan Allison1 Comment

I often wonder if governments really focus on the issues rather than responding to incidents. In the case of pedestrians and the City of Sacramento, is the city really placing its attention, and its dollars, where they need to be to enhance the safety of pedestrians? I’ve created some maps to show where the problems lie (see note at bottom about data sources and how these were created).

The collisions mapped are:

  • Date: 01-01-2004 to 12-31-2012
  • Location: City of Sacramento only (no, I can’t explain why some are outside the city)
  • Victim role: Pedestrian
  • Victim degree of injury: Killed or Severe Injury
  • 388 collisions
  • ArcGIS link

The first map, a point map of the entire city, shows:

  • the greatest density of collisions is in downtown/midtown, but there are certainly plenty in other areas
  • almost all collisions happen at intersections, not mid-block
  • almost all collisions are associated with major streets, called arterials and collectors, which are wide and high speed, intended to move motor vehicle traffic at speed rather than provide for multi-modal transportation

pedestrian collisions, killed or severe injury
pedestrian collisions, killed or severe injury, point map

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