I noticed an issue with end conditions not tying into the existing ground line drawn in cross section cells. The problem occurred at several cross section and the error varied between 0.01' to upwards of 2'. After troubleshooting, it was noticed that there are differences between the TIN file and the DTM file. The DTM file was creating by converting the TIN surface into a DTM surface readable by Roadway Designer. The existing ground lines in the cross section cells were drawn in using a TIN. If I cut existing ground line using the DTM created the the same TIN file there are differences between the two. The proposed DTM model then ties perfectly into the existing ground surface in a DTM format, but this file is no longer accurate as it does not triangulate in the same way as the TIN file, creating erroneous triangles and causing differences of elevation up to 2'.
Any ideas why these two formats of a surface would not be ide
ntical?