Alike line definitions, color spaces and fonts used in maps - pictograms probably have the biggest impact on readability and usability.
Weird examples are plenty ... signal or noise?
What to do if you need to display many different features, POIs, levels, layers ...? What did classical cartographers do?
Reduce it, overlap it, colorcode semantical aspects and meaning ...?
Neither approach seems satisfying.
We decided to design our own set of symbols and pictograms.
As FF Transit caters around 600 chars, glyphs and symbols, we initially hoped that this would cover our immediate need. Turned out: it didn't. It's original use case clearly was to act as a corporate font for a large public mass transport provider. Repurposing the symbol set as a general tool for large scale maps certainly is a different angle.
Consequently our approach of diving deeper into large scale maps called for distinctive iconography.
Where to start? There are literally thousands of symbol icon sets out there and all seem to build upon another. You'll see the same symbology more or less cited, copied and migrated over the last decades.
Particularly "AIGA/D.O.T signs & symbols" have influenced almost all other designers - starting from "The Parks Font" made for the U.S. National Parks Service up to the UK Ordnance Surveys' symbol set for its POIs. Even ESRI's ArcGis suite is delivered with literally hundreds of symbol sets.
None of those exiting sets came close to what we needed: a visual language to render maps for any device. (OK: as many use cases as possible)
We designed just another set, depending on learned meanings and trying to minimize cultural dependencies. Here's what our current development stage looks like:
Hot or not?
Throw your log on the campfire - tell us what you think!
@Pictograms: I thought a lot about icons and pictogramms in online maps that cover the whole world. And I came to the conclusion, that the world is just too complex for "one icon set fits it all"-solutions. Just take a simple example of icons for public transportation. The ones you developed will work perfectly in Germany, but already in Austria different symbols for S-Bahn and Tram (Bim) are used. So should a German visitor in Vienna see the green S-Bahn-sign (because he is used to it and knows what it means) or should he see the Austrian version of it (which would help him to identify S-Bahn-signs in reality)? Should there be a legend? Should the user be able to determine his own preferences? Hu, what an interesting topic... I would love to discuss this in more detail! Campfire anyone? :)
The plan today is to adapt localize symbols and deliver them in sort of a language file. No idea if that works or scales. We'll see.
What would your best practice be?