I have been trying to create a surface of a corridor I created. The corridor itself is somewhat complex, having 5 different assemblies, varying from 2 to 4 lanes, and accept/reject curb and gutter. The grades on the roadway lanes all come out fine, but for some reason, certain parts of the curb and gutter come out wrong. It seems that some of the flange/flow lines are used as breaklines, some aren't. The road cross slopes are 2%. the curb and gutter 4%, so there should be a noticeable grade break at the curb, but in some areas, the contours jump forward to the top of curb, ignoring the flowline. I have tried using Corridor properties/surfaces/add date, and using the flange/flow/toc as feature lines, but this doesn't help. Any ideas?