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!