So here is my situation:

I have a road segment that is one feature. Along this road I have data that is captured via GPS pings (which generally occur every 5 seconds), and are delineated by 'START_DATE' and 'END_DATE'; so there are multiple pings that make up the information per 'capture' or row.

Road Segment (one feature) START//END DATE

The question I have is with the fact that I have multiple rows of values that encapsulate the entire segment and therefore occupy the exact spatial area of the line.

One of the columns in the table is 'QUANTITY_SOLID', which contains the total amount of solid materials that were disseminated during that 'START_DATE / 'END_DATE' instance.


I then attempt to symbolize by 'Quantities > Graduated Colors'

Graduated Colors

I understand that because it is only one feature class, and all of the information contained in the rows along that line segment all cover the same singular feature class, that there will not be any differentiation between the colors when symbolized.

However, this leads to my actual question: How does ArcMap choose what color to make the line if there are multiple values over the same spatial area? Does it take the sum of all the 'QUANTITY_SOLID' and average them? Or something else?

1 Answer 1


I might be missing something, but I think your problem may be that all your lines are in fact showing up, it's just that since they are all the same width, you can only actually see the top-most feature and that one is covering up all the lines underneath it. If you want to be able to see all the records that occupy the same linear space, you will need to change the symbology. There are a number of ways to do it:

  • If you're only interested in the heaviest application of materials, you can use Symbol Levels (click the Advanced button in your last screenshot above) to make the red line show up on top of all the others.
  • You could offset your different line symbols so they show up next to each other rather than on top of each other, or make them different widths.
  • You could use the Symbol Editor to change your line symbol to a Marker Line and add a marker feature to each line symbol, using a different marker interval for each class in your symbology.
  • hah, I feel so stupid, I definitely think I need to take a break from looking at Oracle/ArcMap/etc. Thank you for your help, I appreciate the effort and i'll definitely look into changing the symbology! Aug 5, 2014 at 17:01

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