In the uk there is generally a cross over between what the bridges designer and the highways designer would do in relation to civil engineering. Bridge designer would only do the concrete support elements required in there design and the highways engineer would do the rest of the build up above that(tarmac, kerbs,etc). So generally we would just apply a sloping floor for a given thickness between supports as we would import the build up above this from the civil 3d model.
That doesnt help you directly but actually being able to complete this take you will firstly need to decide where this component is going to live within revit(Floor/Framing/Generic). If you would want it within a Floor category then this will only be able to be done via the model in place component.
I would suggest a beam or generic family type so it can be set up as a family element, then you set up a profile family file with all the profile elements as a variable then import that into this new family file. Then setup the family accordingly with either a sweep or swept blend depending on if the profile is variable along its length.
Once all that is done you can get dynamo to apply say the revit framing family along a curve element and set up its profile settings but dont forget you will need to break the applying curve lines up at each profile change prior to applying the family member.
Hope this helps,