I plan to develop a network of physical widgets all over the city to inform pedestrians about current Air Quality Index in their neighborhood. This is needed to improve people conscious about their environment pollution to start them acting against.

I need to create that widget to visualize current AQI, so information like here: http://earthzine.org/wp-content/uploads/2010/01/Airquality.jpg

This is:

  • one of 6 colors
  • and up to 3 digits number

It should be possibly cheap and easily recognized form moving vehicles (target: public transport) and from some distance.

I plan to put those widgets in friendly venues (shops, offices, even flats).

Just for reference, here http://www.livinglightseoul.net/ is an example of such installation.

  • Do you only want to show the current index - or a card with all the possible indexes?
    – icc97
    Commented Jan 27, 2016 at 14:40
  • updated question to be more precise Commented Jan 27, 2016 at 14:52

3 Answers 3


I would suggest a series of simple smiley face graphics for the rating. Advantages:

  • Instantly recognizable
  • No problem for color blind people.
  • More likely to stand out as unique in a street setting. Something based on green/yellow/orange/red colors would be competing with many other signs and lights that use these colors to communicate information.

If you need six levels, you could use something like:

  • Wide smile
  • Slight smile
  • Indifferent (straight line mouth)
  • Slight sad face
  • Very sad face
  • Face that looks ill (tongue sticking out)

A simple graphic like a smokestack next to this may communicate the meaning.

  • I agree, index is misleading. Is 0 better than 100? How much? What's that number? Commented Jan 27, 2016 at 14:43
  • I think this is why information is normally given in two ways: those who are not "AQI literate" will recognize color but the number is quite useful for people who know a little bit about the subject and want to know precisely "where we are at the scale 0-500". Commented Jan 27, 2016 at 14:55
  • From the pit of my ignorance I'd say very few people will recognize what 500 is. I'd even guess they will think, "WOW, air quality is 500. It's better than that poor people with just 400 (higher quality index is better)...". Commented Jan 27, 2016 at 15:42
  • You're right, especially that people who recognize what 500 is are most probably able to check that 500 online somewhere. Commented Jan 27, 2016 at 21:28
  • I've found similar approach implemented in Shanghai, check those pokemon style children semc.gov.cn/aqi/home/English.aspx Commented Feb 15, 2016 at 11:17

Given that you want people to recognise what it is from vehicles - you need to have one icon that is instantly recognisable as air quality.

Then combine it with the colour and number, or possibly easiest to show is the opposite - air pollution.

The noun project has lots of icons for pollution

enter image description here

Icon credit: Amelia Wattenburger

Update - here's another version as the 200 won't mean much

And potentially modify the amount of smoke coming out as an extra visual clue.

enter image description hereenter image description here


If you want to make these statistics visible to motor vehicles I would take a page from the US Forest Service which already implemented a very similar scale for signs warning of risk of forest fires:

enter image description here

enter image description here

You can of course include the numbers and labels but what really matters is where the current level is pointing into relation to the scale of values and the color indicating good/bad. At a quick glance a car driving by can see that if the "pointer" is at the far right of the scale in the red zone then the emission level is high.

  • 1
    This is a good suggestion. One possible downside: it takes a lot of space to show the whole scale, so it might not work so well in urban areas.
    – user31143
    Commented Jan 28, 2016 at 7:17
  • Yeah it will be rather difficult to fit it. Commented Jan 29, 2016 at 15:46

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