Creating Accessible Maps - Using ArcGIS Pro 3's New 'Color Vision Simulator'
I have been (and am still) guilty of designing maps and graphics without testing them for accessibility. My excuse has always been that most of my maps are for quick illustrations or demonstrations and that it would simply take too long. Not the best excuse.
When students are new to GIS and cartography, they may not even consider accessibility. Or they simply may not know how or what to test/look for. With so much to learn for new students, it can be easy to overlook map accessibility.
One of the new features in ArcGIS Pro, that I think can become a mainstay of cartography labs and lessons are the Color Vision Simulator tools in ArcGIS Pro. These provide a really quick/easy way to prompt students with an important question… ‘Does your map really work for everyone’? I think this can also be a great bridge into other discussions/conversations around how maps are interpreted through different social/political/cultural lenses. What does map accessibility really look like?
For example, here’s my first stab at creating a basic choropleth map showing poverty rates across the US. My color choices are interesting, but it works… right?
With ArcGIS Pro 3.0 – there is a new toolbar in the View ribbon, that lets you toggle between 3 different color blindness simulations: deuteranopia (green blindness), protanopia (red blindness), and tritanopia (blue blindness).
With just a simple toggle, I can test to see what my map looks like with the simulations. My map below shows the symbology with a protanopia simulation, and it highlights a really big issue with my symbology choice. With the red color family now removed… the contrast between the blue colors is really subtle.
Similarly, if I toggle the simulator to display the map for tritanopia (blue blindedness), this map works to some extent, but the middle range values stand out more than I would like them to.
In my example, I finally arrived on a BW map, which as every old-timer knows, is also going to work well when it’s printed, or photocopied. Or, you could introduce symbology concepts like textured fills that would work well for print or color blindedness.
This was just one small enhancement to ArcGIS Pro, but I think it provides a really valuable way to start discussions, or have assignments based around accessibility. Color blindness is obviously just one small example of how a population can be affected by map design, but this new tool helps to present it to students in a way that can be really hard to forget or ignore.