[ORD 2020 R1 and R2] - Sight Visibility sections disappearance

Hi, I would like to highlight a problem we have had on several occasions with sight visibility sections / results disappearing.

We often use terrain models as design surface in sight visibility tool. We typically create sight visibility sections in a separate container file to which the terrain model(s) and corridors are attached. In this file we usually create multiple sight visibility sections as needed for separate lanes and perhaps in specific locations.

So what we found is that if the reference design surface triangulation is re-created as a new terrain model (in its own file) then the sight visibility sections disappear in the visibility container file. This same concerns terrain model used as existing surface. We reckon this is another victim of broken relationship due to element ID change. When new terrain model is created (even using the same model name) a new element ID is assigned.

In fact the change of element ID affects all reference elements used in the sight visibility sections, such as: alignment, corridor, strings defining eye and object (either as part of corridor or separate model) and the surfaces.

This is very dangerous as many hours of work can be lost since sight visibility analyses can take long time when trying to optimize widening. The only way to get the sight visibility sections back seems to be by retrieving the original terrain model file from and the sight visibility file from a backup. Note, retrieving the terrain model file only is not sufficient.

Another problem is that not all types of terrain model can be updated without re-creating the models as new entities. For example I am not aware of a way of updating terrain from mesh other than creating new terrain (using updated source data).

Note, that if a corridor is updated and its element ID doesn’t change but element ID of the eye string and / or object string change (when a template drop is deleted and a new applied) then the affected sight visibility sections disappear. Similarly, when a template drop is changed using a template that doesn’t produce the string name that was used as the eye and/ or object in the sight visibility sections.

Also, there is no way to update the sight visibility sections when the design surface, alignment or corridor change (if used). So, the change to these elements should not matter and definitely we should not lose the sight visibility sections. Sight visibility analyses are fundamental and critically important elements of highway design and modelling workflow.

Has anybody else experienced this issue before and reported a defect? Or am I missing something in this workflow?

Regards,

Mariusz