Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

I need to plot lines onto a map to display road quality. I'm already using colours to distinguish between different road conditions, but I also need to display another factor - the survey origin.

There are only two different origins to display, but I'm not sure what's the best way to do this. Dashed lines with gaps are not appropriate as surveys can legitimately contain gaps.

My current approach is to display the two types as follows:

  1. Solid colour lines for one of the survey types.
  2. For the second type, use a dashed line, but with the gaps drawn in a lighter shade of the same colour (shown below).

However it still seems a little confusing to see where surveys start and end.

Are there any alternatives or best practices to follow?

enter image description here

share|improve this question

Since you are already symbolizing by road condition (which I'm guessing may be represented by a few colors), I would suggest to not use a multi color dash line to represent survey origin (sometimes less is more). I generally use a buffer/fade effect for displaying multi attribute line info, see caption below.

enter image description here

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.