Functional Part: Intersection

Name

Intersection

Identifier

fp_intersection

Overview

This functional part defines the requirements for modeling and exchanging intersection information in a highway BIM environment. Intersections are critical junction points where two or more roadways meet, requiring coordinated geometric design, traffic control, and safety analysis. Intersections range from simple two-way stop-controlled junctions to complex signalized intersections and roundabouts.

The functional part supports multiple use cases across the project lifecycle:

  • Traffic operations analysis: Integration with traffic simulation and capacity analysis tools
  • Safety evaluation: Coordination with crash data and sight distance verification
  • Signal and signing design: Placement of traffic signals, signs, and pavement markings
  • Geometric design: Turn lane layout, island placement, and pedestrian accommodations
  • Asset management: Long-term tracking of intersection assets and performance monitoring

This functional part represents intersections as point features with associated property sets for location, type, control method, and geometric configuration.

Results

Purpose

The purpose of this functional part is to standardize the exchange of intersection information between BIM authoring tools, traffic analysis software, and asset management systems. By providing a consistent data structure, this functional part enables identification and classification of intersection types and control methods, integration with traffic capacity analysis tools (HCS, Synchro, VISSIM), coordination of signal equipment and signing design, safety analysis and crash data integration, and asset data handover to transportation agencies for operations and maintenance.

Concepts

Information Needed Entity/Pset/Functional Part MAN REC OPT NOT
Intersection name designation Pset_IntersectionGeneral.IntersectionName IfcPropertySingleValue::IfcLabel X      
Intersection type classification Pset_IntersectionGeneral.IntersectionType IfcPropertySingleValue::IfcLabel X      
Control type method Pset_IntersectionGeneral.ControlType IfcPropertySingleValue::IfcLabel X      
Number of approaches Pset_IntersectionGeneral.NumberOfApproaches IfcPropertySingleValue::IfcInteger   X    
Design vehicle type Pset_IntersectionGeneral.DesignVehicle IfcPropertySingleValue::IfcLabel   X    
Unique identifier for intersection element IfcCivilElement.GlobalId IfcGloballyUniqueId X      
Object identification code Pset_Identification.ObjectID IfcPropertySingleValue::IfcLabel X      
Feature designation code Pset_Identification.FeatureID IfcPropertySingleValue::IfcLabel   X    
Feature description text Pset_Identification.FeatureDescription IfcPropertySingleValue::IfcText   X    
Survey feature code Pset_Identification.SurveyFeatureCode IfcPropertySingleValue::IfcLabel   X    
Referenced alignment identifier Pset_AlignmentDataLinear.AlignmentIDReference IfcPropertySingleValue::IfcLabel X      
Referenced corridor identifier Pset_AlignmentDataLinear.CorridorIDReference IfcPropertySingleValue::IfcLabel X      
Begin station value Pset_AlignmentDataLinear.StationBegin IfcPropertySingleValue::IfcLengthMeasure X      
Begin station offset Pset_AlignmentDataLinear.StationOffsetBegin IfcPropertySingleValue::IfcLengthMeasure X      
End station value Pset_AlignmentDataLinear.StationEnd IfcPropertySingleValue::IfcLengthMeasure X      
End station offset Pset_AlignmentDataLinear.StationOffsetEnd IfcPropertySingleValue::IfcLengthMeasure X      
Reference point location Pset_AlignmentDataLinear.ReferencePointLocation IfcPropertySingleValue::IfcLabel X      
State plane northing coordinate at begin Pset_StatePlaneCoordinatesLinear.NorthingBegin IfcPropertySingleValue::IfcLengthMeasure   X    
State plane easting coordinate at begin Pset_StatePlaneCoordinatesLinear.EastingBegin IfcPropertySingleValue::IfcLengthMeasure   X    
State plane northing coordinate at end Pset_StatePlaneCoordinatesLinear.NorthingEnd IfcPropertySingleValue::IfcLengthMeasure   X    
State plane easting coordinate at end Pset_StatePlaneCoordinatesLinear.EastingEnd IfcPropertySingleValue::IfcLengthMeasure   X    
LRS postmile begin value Pset_LRSDataLinear.PostmileBegin IfcPropertySingleValue::IfcLengthMeasure     X  
LRS postmile end value Pset_LRSDataLinear.PostmileEnd IfcPropertySingleValue::IfcLengthMeasure     X  
LRS route identifier Pset_LRSDataLinear.LRSRouteID IfcPropertySingleValue::IfcLabel     X  
GPS latitude at begin Pset_GPSCoordinatesLinear.LatitudeBegin IfcPropertySingleValue::IfcReal     X  
GPS longitude at begin Pset_GPSCoordinatesLinear.LongitudeBegin IfcPropertySingleValue::IfcReal     X  
GPS latitude at end Pset_GPSCoordinatesLinear.LatitudeEnd IfcPropertySingleValue::IfcReal     X  
GPS longitude at end Pset_GPSCoordinatesLinear.LongitudeEnd IfcPropertySingleValue::IfcReal     X  
GPS control point reference Pset_GPSCoordinatesLinear.GPSControlPoints IfcPropertySingleValue::IfcText     X  

Examples

Example 1: Signalized Intersection Traffic Analysis

Use Case: Exchange intersection geometry and control data from design model to traffic analysis software for capacity evaluation.

Scenario: A new signalized intersection at a highway and arterial crossroad requires capacity analysis to determine level of service and signal timing requirements.

Data Flow:

  1. Designer models intersection geometry with turn lanes and approach alignments
  2. Intersection data exported to IFC with control type and approach count
  3. Traffic engineer imports IFC into analysis software (Synchro/HCS)
  4. Software extracts intersection configuration and lane geometry
  5. Traffic volumes applied and capacity analysis performed

Key Information Exchanged:

  • Intersection: “US-Highway-20 @ Main Street”
  • Type: “Conventional signalized intersection”
  • Control: “Traffic signal (pre-timed)”
  • Approaches: 4 (North, South, East, West)
  • Turn lanes: Dual left-turn lanes on major road approaches
  • Design vehicle: WB-67 (semi-trailer truck)

Example 2: Roundabout Geometric Design Exchange

Use Case: Exchange roundabout geometry including inscribed circle diameter, entry/exit radii, and splitter island dimensions between design platforms.

Scenario: A single-lane roundabout replaces an existing stop-controlled intersection. The geometric design must be exchanged from design software to visualization tool for public engagement.

Data Flow:

  1. Designer creates roundabout geometry per NCHRP 672 guidelines
  2. Roundabout parameters exported to IFC including circle diameter and entry angles
  3. Visualization specialist imports IFC into rendering software
  4. Roundabout geometry rendered with landscaping and signage
  5. Visualizations used in public meeting to explain roundabout operation

Key Information Exchanged:

  • Intersection: “SR-45 @ County Road 15 Roundabout”
  • Type: “Single-lane roundabout”
  • Inscribed circle diameter: 130 feet
  • Entry radii: 60 feet (all approaches)
  • Splitter island length: 35 feet minimum
  • Design speed: 20 mph (circulatory roadway)

Example 3: Intersection Asset Inventory Handover

Use Case: Transfer as-built intersection asset data to transportation agency GIS system for operations and maintenance.

Scenario: Upon project completion, all intersection assets (signals, signs, pavement markings) must be registered in the agency asset management system with accurate locations and installation dates.

Data Flow:

  1. Contractor delivers as-built BIM model with intersection point features
  2. Intersection data exported to IFC including location and equipment inventory
  3. Agency imports IFC into GIS-based asset management system
  4. Intersection assets registered with unique IDs and maintenance schedules
  5. Signal maintenance crews access intersection data via mobile devices

Key Information Exchanged:

  • Intersection ID: “INT-2025-0312”
  • Location: “Latitude 40.123456°, Longitude -85.654321°”
  • Signal controller: Econolite Cobalt (Cabinet Type 332)
  • Signal heads: 16 (12-inch LED)
  • Detection: Video detection (4 cameras)
  • Installation date: 2025-08-15