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Sample for future IFC road

Hello,

I’m looking for samples regarding decomposition of road in the next IFC release (ifc4x3-ifc-road-first-draft).

For example:
If we consider the attached schema. It is a cross of 2 road composed of 2 ways. What will be the project’s decomposition ?

Following is a proposal for such example:
Is it correct ?

• IfcSite
• IfcRoad
o IfcLongitudinalRoadPart\ SEGMENT
- IfcLateralRoadPart\TRAFFICLANE
- IfcLateralRoadPart\TRAFFICLANE
o IfcLongitudinalRoadPart\ INTERSECTION
o IfcLongitudinalRoadPart\ SEGMENT
- IfcLateralRoadPart\TRAFFICLANE
- IfcLateralRoadPart\TRAFFICLANE
• IfcRoad
o IfcLongitudinalRoadPart\ SEGMENT
- IfcLateralRoadPart\TRAFFICLANE
- IfcLateralRoadPart\TRAFFICLANE
o IfcLongitudinalRoadPart\ SEGMENT
- IfcLateralRoadPart\TRAFFICLANE
- IfcLateralRoadPart\TRAFFICLANE

Furthermore, how IfcVerticalRoadPart does it fit with all of this ?

Thank you in advance,
Kevin.

To what extend does ifc cover topo, faces, meshes, alignment, etc.? The reality is that this is done in either GIS or DWG. What brings IFC to be able to change the current pratice? Apart from that it is “open”. Just curious.

@kevin.nahaboo your proposal seems correct. However, the spatial structure is still a hot topic in the harmonisation work within the IFC Common Schema project. As of today, there are no Ifc-Lateral/Longitudinal/Vertical-RoadPart, but rather an IfcFacilityPart with a special attribute denoting the decomposition to be lateral/longitudinal/vertical. This is still not set in stone, pay attention to the expert panels and news from the InfraRoom and RailRoom.

What is foressen is also a relationship IfcRelInterferesElements, where you can denote that one IfcRoad crosses the other IfcRoad.

Additionally, perhaps you would like to denote, that the intersection is a part of the other IfcRoad: for that, a reuse of IfcRelReferencedInSpatialStructure is foreseen (https://standards.buildingsmart.org/IFC/RELEASE/IFC4/ADD2_TC1/HTML/link/ifcrelreferencedinspatialstructure.htm).

As of where the vertical decomposition comes in: have you considered splitting the road to above / below ground?

@Hans_Lammerts: I don’t see how your question relates to the topic. But to answer this as well:

For how IFC changes current practice - can you elaborate on that? (perhaps start a new thread, though).

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In short. I have been following infra ifc for at least decade and i don’t see anything ‘moving’ in civil design worlds. Where is the the user demand based upon? To design in native IFC?? just don’t see the point in putting efforts in objects like ‘road’ and ‘rails’ topo etc. Sorry

Thank you @stefan.markic for the explanation.