I know similar questions have been asked about this already, but I would like to check something specifically... I have a copy of a published 1:1m map of Ivory Coast which states (in the legend) that it's projected in UTM30N, WGS 84. The problem I am wondering about is that the map spans zones UTM30N and UTM29N, so doesn't this mean that there is likely to be quite a lot of distortion across the map? Wouldn't lat-lon have been a more appropriate choice for such a map? I'm intrigued and would like to know what others think, because it's an official, published map and its authors must surely know more than I do about this!

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    No, a geographic coordinate system is not likely to be better than a projected CS for such a small area. Choice of projection is surely a jugement call on the part of the cartographer or mapping agency, but not something that be questioned in GIS SE, since it's too opinion-based to provide a correct answer. Once you have sufficient reputation you could ask this in our Geographic Information Systems Chat, though it's not a heavily utilized feature. – Vince Sep 1 '17 at 12:02
  • If you "know similar questions have been asked about this already" what were they? Please provide links to them. – PolyGeo Sep 1 '17 at 18:58
  • Opinion-based? 1. People like to measure in meters or feet rather than degrees and it's lot easier to measure distances or areas;. 2. Map scale is more consistent across the map than it would be in a GCS; 3. UTM conserves shapes/angles so data looks "better"; 4. Publisher? Some agencies just have a standard that UTM is used for almost everything. – mkennedy Sep 1 '17 at 20:24