Hello, It sounds like you have quite a complex polyline layer, and I cannot guarantee that this can cope appropriately, but I have been using the ET geowizards addon which has a function called split polyline with the option of splitting into specific lengths or number of equal lengths. I'm not sure whether you need a license for that number of features but it has been working fine for me with the free unlicensed version for smaller line splitting tasks - probably worth looking into at least. http://www.ian-ko.com/ All the best, Bex
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