I've just recently ran into this problem, I can't find the answer anywhere else...
We were recently doing a simple water main extension in a rural area. We wanted to use the centerline of the road as the alignment (since it's an existing road and a good benchmark for the contractor) and show the water main on the roadway celterline alignment and profile. On the roadway centerline alignment and profile, I then wanted to show the profile of the existing ground over the proposed water main. We tried using the "Sample Offset" when creating the profile from surface, but the water main wasn't equidistant from the centerline. I then wanted to just make the watermain polyline into an alignment, but even a slight change to the alignment (1 foot total) would throw off my stationing by 1 foot from the point of the change to the end of the alignment.
Is there a way make a profile have a "master" alignment and then follow a "slave" alignment for a profile display? Similar to how a corridor for a turn lane can follow a secondary alignment when tapering.
You help is greatly appreciated.