I have a corridor with a cul-de-sac at the low point. Since I want to keep the vertical alignment of the centerline, I used the basic lane transition to stretch out to the curbline. I have also defined an alignment along the c-d-s curbline.I want to export the feature line @ ETW as the vertical alignment component (profile) for the curbline - then attach an assembly for the curb/sidewalk around the c-d-s. I added the ETW feature line in the Surfaces tab of the Corridor properties dialog box.
When I rebuild the surface, I can't select the feature line...
Have you exported the surface using the "Corridor> Export" tool. If so, turn off the layer with the exported surface on it and try to select the feature line. I ran into this yesterday when trying to create a "Render Only" boundary on a corridor that I had just exported the surface from. It seems that the surface breakline was on top of the corridor feature line and when I tried to select the feature line I got a command line message that said "No feature line selected". I deleted the surface from the surface collection then it worked fine. I would assume that turning off the layer would save you having to delete the surface.