Thanks for the advice, I have never really thought about the issue of over modeling. I'm a bot or a perfectionist when it comes to civils and model most of the detail in.
In this case I will use a label to "fake" the height at the top.
As for the planning in this case the speed humps were a requirement of the client along with narrowing as they are trying to keep the speed down to 15mph. I do see what your saying though, speed humps have no place on minor or major traffic routes.
I do terrain modeling in C3D for machine control. I also do 3d renderings for presentations. For machine control, I model subgrade. That's what our machines grade to. A finish grade model for machines is too much trouble. I build very complex and detailed models since that guides our machines, but I would never need speed humps in a model for machine control. I don't think I would take the time to do it for a presentation model either. I may put a yellow stripe across the road in their locations. It's just way more trouble than it's worth in my opinion.
I was a dyed-in-the-wool hater of speed humps. Then a drunk teenager in our neighborhood got into his daddy's Corvette and did a Daytona 500 around our 'hood. He lost control, flew into a parked RV with an elderly couple sleeping inside, and killed them both instantly. The city installed speed humps within a month and now traffic flows at no more than 25 mph. The humps cause a minor but acceptable vertical acceleration, they eliminate speeding in what was otherwise a wide, straight street at moderate slope which enticed speeds of 35 to 40, and everybody in the neighborhood is very happy with them. If nothing else, they force "outlanders" to seek another route, which is fine by us.
So, what are the other choices? Design very narrow streets with lots of parking, very curvy streets where higher speeds are not likely, or some kind of speed modifications like humps or chicanes or the like. Personally, the humps are my preference in residential settings. Properly designed, one can drive them easily at 25 mph, ande spaced properly, no one accerlerates between them, and they have gaps in between to allow emergency vehilces to, essentially, avoid the interuption. As for flying motorcycles... drive safe like the rest of us.
For our more detailed work which requires technical approval by the local authorities prior to construction, we now have to show speed tables on the carriageway profiles and on the contour plans. I've previously had a number of councils complain that our plans didn't show the 'real world' road surface on the plans or where they are on the longitudinal sections.
Furthermore, the local design standards for some authorities specifically require us to put in speed tables, tabled junctions etc as opposed to more bends etc.. In fact, some layout architects use speed humps as a way of manipulating the highways layout to increase the developable area.
We're based in England so things may be different elsewhere with less bureaucracy!
The way we do all this is by using raised sub-assemblies first then when the highways are technically approved, manually inserting 3D polylines representing the table/ramp edges if we need more detail (it's much quicker).
This is the solution I have used and I think it works well.
1. Do you longsection and corridor design as normal.
2. Then go to the profile and create a new profile called ramp or whatever suits.
3. Draw the ramps onto the longsection.
4. Create a new corridor with a road only assembly.
5. Now split it into regions for ramps and non ramps
6. Set a new blank assembly up called none (just the marker)
7. Set the blank assembly to any part of the road without a ramp.
8. Now create a new surface called finished, final, etc...
9. Paste the main corridor surface first then paste the ramp surface (You will have to manualy delete the stray triangles in the ramp surface, takes no time at all)
10. Turn you main and ramp profiles off through the style and add the finished surface to the longsection.
This may look long winded but once you have done is once or twice it will be quick. It took me 15mins to design 4 ramps which also included narrowings. This also means the ramps will follow any superelevations you may have if you near a corner or change in chamber/crossfall.