Can an object or a line of objects be arranged to follow contours?
e.g. a line of kerbs (from a family, including build up and specification etc., not just a placeholder)
Or, is Revit the wrong tool? I'm happy to hack a plugin to make this work as my company has already made the investment, but the Autodesk infrastructure tools might be the right option.
Curse you landscape architecture for falling through the software provision cracks!
You could create your families such as kerbs using the "Structural Framing - Beams and Braces" template and then either use the API or user interface to place them as beams along selected curves. It's a little hackish in that if your rvt file is being used by other consultants they will need to know about these "Beams" and filter them out of their schedules and views accordingly.
A more pure way would be to use the "Line Based" template but unfortunately you will be limited to straight lines only. You could work around this by tessellating any arcs encountered using the API.
I've not had much experience with the MEP families and associated tools such as pipes and ducts. It might be worth your while to check those out too to see if something there is a better fit.