Accessible map with polygons

Dear colleagues and friends,

There’s a project at work where we want to show the distance someone can travel within a given time from their current location. We want to do this by drawing polygons around a specific point on the map. These polygons would vary in colour & pattern and we’d have a legend next to the map that would indicate what all the different colours/patterns mean.

We can tick off colourblindness because we have the patterns, we can even make the legend accessible if we include colour/pattern combinations in text. However, I’m unsure how to make the rest of this map accessible. We can give the polygons an aria-label, something like “5 minutes” and “15 minutes”, but that’s not gonna do any good as you’d still have no idea what is within that polygon if you can’t see the darn thing.

Does anyone have experience with this or any ideas on how to solve this?

Talk soon.
— Michiel