¶ 3 Route planning
¶ Model hierarchy
| IfcProject | |||||||||
| IfcSite | |||||||||
| IfcFacility | By the route type: IfcRoad or IfcRailway (or IfcMarineFacility) | ||||||||
| IfcAlignment | Stationing reference line (and other significant alignments) | ||||||||
| IfcAlignmentHorizontal | Horizontal alignment geometry and segments for parameters | ||||||||
| IfcShapeRepresentation | RepresentationType = Curve2D (Axis representation) | ||||||||
| IfcCompositeCurve | Horizontal curve used for linear placements | ||||||||
| IfcCurveSegment | Segment of composite curve cut from: -IfcLine, -IfcCircle or -IfcClothoid (or other type of transition curve) |
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| IfcAlignmentSegment | Horizontal parameters segments | ||||||||
| IfcAlignmentHorizontalSegment | Horizontal line, circular or transition segment | ||||||||
| IfcClassification | Horizontal alignment coding | ||||||||
| IfcAlignmentVertical | Vertical alignment geometry and segments for parameters | ||||||||
| IfcShapeRepresentation | RepresentationType = Curve (Axis representation) | ||||||||
| IfcGradientCurve | Vertical curve based on horizontal IfcCompositeCurve | ||||||||
| IfcCurveSegment | Segment of gradient curve cut from: -IfcLine, -IfcCircle or -IfcPolynomialCurve (parabola) (or other type of transition curve) |
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| IfcAlignmentSegment | Vertical parameters segments | ||||||||
| IfcAlignmentVerticalSegment | Vertical line, circular or parabolic segment | ||||||||
| IfcClassification | Vertical alignment coding | ||||||||
| IfcAlignmentSegment | Cant parameters segments | ||||||||
| IfcAlignmentCantSegment | Line segment or transitition curve segment | ||||||||
| IfcClassification | Cant alignment coding | ||||||||
| IfcClassification | Alignment coding | ||||||||
| IfcAnnotation | Design parameters | ||||||||
| IfcClassification | Route (road, railway, waterway) classification | ||||||||
| IfcShapeRepresentation | RepresentationType = GeometricCurveSet (Footprint representation) | ||||||||
| IfcGeometricCurveSet | Facility footprint boundaries | ||||||||
| IfcCurve | Footprint boundary segment (or the whole as closed IfcPolyline) | ||||||||
| IfcFacilityPart | Part of road, railway or waterway facility | ||||||||
| IfcAlignment | Other significant alignments | ||||||||
| IfcClassification | Alignment coding | ||||||||
¶ 3.1 Contents
Routes encompass highways, local roads and private roads, streets, waterways and railways.
The route planning data in Inframodel IFC file shall include primarily non-physical design elements and parameters (the physical elements described in the following chapters), in addition to the context information described in chapter 1:
- Site: one (or more) spatial element containing facilities: road, railway, waterway (see chapter 2)
- Facility: one or more spatial element representing the road, railway or waterway being subject to project activities
- Faclility parts: optional spatial elements for breakdown of the facility
- Alignment: one (or more) linear positioning element for linear referencing (stationing)
- Annotation: optional information elements for providing design parameters
¶ 3.2 Facility
IfcFacility, usually instantiated as one of its subtypes e.g. IfcRoad or IfcRailway is placed on IfcSite (the extent of the facility under project activities). IfcFaclility may have a shape representation (such as 2D footprint, 3D top surfcace or 3D volume), and it may contain physical elements, or it may also be spatially broken down in to IfcFacilityPart. Linear facility (road, railway, waterway) usually also contain one (or more) alignment (IfcAlignment); they also may have various design parameters (associated with alignment) as annotations (ifcAnnotation).
¶ 3.2.1 Facility parts
A facility (road, railway or waterway) is broken down in longitudinal or lateral direction using IfcFacilityPart.
Common longitudinal parts of linear facilities:
- SEGMENT: A linear portion of the facility defined by some uniform characteristics, or a transition between segments of uniform characteristics
- JUNCTION: At-grade junction between two or more segments of longitudinal facilities usually of the same type
- LEVELCROSSING: At-grade crossing between two or more different modes of transport
- TERMINAL: A longitudinal facility part that represents a termination segment of a road or railway
Road specific longitudinal parts:
- ROADSEGMENT: Longitudinal, linear uniform or transition segment of a road
- INTERSECTION: At-grade junction where two or more roads meet or cross
- ROUNDABOUT: At-grade junction where traffic streams are directed around a central element
- TOLLPLAZA: A part of road facility where tolls are collected for use of toll road, tunnel or bridge
- RAILWAYCROSSING: At-grade crossing between road and railway
- PEDESTRIAN_CROSSING: Designated level crossing over a road for pedestrians
- BICYCLECROSSING: Designated level crossing over a road for cyclists
Road specific lateral parts:
- ROADWAYPLATEAU: Lateral part of road comprising the carriageway(s), shoulders and medians
- CARRIAGEWAY: Unitary lateral part of road built for traffic, may comprise several kinds of traffic lanes and lay-bys, as well as traffic islands
- TRAFFICLANE: A part of carriageway designated to vehicular traffic for a particular purpose
- LAYBY: A part of road where vehicles can divert from ordinary stream of traffic
- BUS_STOP: A part of road for stopping buses allowing them to draw out of the traffic lanes and wait for short period
- PARKINGBAY: Lateral part of road for parking vehicles
- PASSINGBAY: A widening of an otherwise single lane road where a vehicle may move over to enable another vehicle to pass
- SIDEWALK: A footpath along the side of a road, may accommodate moderate changes in grade (elevation) and is normally separated from the vehicular section by a kerb
- CENTRALRESERVE: A lateral part of road separating two carriageways of the same road or separating traffic lanes and sidewalk.
- TRAFFICISLAND: A central or subsidiary area raised or marked on the carriageway, generally at a road junction or at-grade crossing
- CENTRALISLAND: The center of a roundabout not intended for traffic, can be painted or upraised
- REFUGEISLAND: A raised platform or a guarded area in the carriageway to divide the streams of traffic and to provide a safety area for pedestrians
- SHOULDER: A lateral part of road adjacent to, and usually at the same level as the Carriageway; not intended for vehicular traffic but may be used in case of emergency
- HARDSHOULDER: A type of shoulder that is surfaced, providing for safe use by vehicles in distress
- SOFTSHOULDER: A type of shoulder that is not surfaced
- ROADSIDE: A lateral part along the road facility adjoining the outer edges of the shoulders; comprising the areas outside roadway plateau not intended for vehicles
- ROADSIDEPART: Various parts of the roadside; side slopes, roadside ditches, back slopes, bunds etc.
¶ 3.3 Alignment
Each route has one continuous stationing reference alignment as IfcAlignmentHorizontal with a vertical alignment as IfcAlignmentVertical; these are nested in IfcAlignment using IfcRelNests.
¶ 3.3.1 Horizontal alignment
IfcAlignment horizontal geometry and semantic decomposition represented as IfcAlignmentHorizontal.
¶ 3.3.2 Vertical alignment
IfcAlignment vertical geometry and semantic decomposition represented as IfcAlignmentVertical.
¶ 3.3.3 Cant alignment
IfcAlignment cant geometry and semantic decomposition represented as IfcAlignmentCant.
¶ 3.4 Alignment segment types
Alignment Horizontal Segment types:
- LINE
- CIRCULARARC
- CLOTHOID
- CUBIC
- BIQUADRATICPARABOLA
Alignment Vertical Segment types:
- CONSTANTGRADIENT
- CIRCULARARC
Alignment Cant Segment types:
- CONSTANTCANT
- LINEARTRANSITION
- BIQUADRATICPARABOLA
- BLOSSCURVE
- COSINECURVE
- SINECURVE
- VIENNESEBEND
¶ 3.5 Desing parameters
IfcAnnotation can be used to capture route design parameters...