SuperElevationCurve

Road superelevation or banking angle profile

Since R2026a

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    Description

    The SuperElevationCurve object represents the road banking angle (superelevation) profile as a function of distance along a road.

    A superelevation curve is an ordered collection of control points, called superelevation nodes, connected by spans that define how the banking angle varies continuously with distance along the road center line. Each node specifies a banking angle at a specific distance along the road, while each span interpolates between two adjacent nodes to create a smooth banking transition. Every RoadRunner road automatically contains a SuperElevationCurve object with default nodes at the start and end of the road. By inserting additional nodes or updating existing ones, you can define uniform or non-uniform banking for straight or curved roads. The SuperElevationCurve object works independently of road geometry and applies consistently to both straight and circular road segments.

    RoadRunner scene canvas showing the superelevation curve, superelevation node, and superelevation span

    Creation

    To retrieve a SuperElevationCurve object, extract the SuperElevationCurve property of a road in your RoadRunner scene. Every road contains a SuperElevationCurve that defines how the road banking varies along its length. For example, given a Road object, rrRoad, the expression seCurve = rrRoad.SuperElevationCurve returns the SuperElevationCurve object seCurve associated with that road.

    By default, the SuperElevationCurve contains two nodes: one at the start of the road (distance = 0) and one at the end of the road (distance = total length of the road). You can insert additional nodes at intermediate distances to define non-uniform banking for straight or curved roads. RoadRunner creates and manages the SuperElevationCurve of a road automatically, you cannot delete it, but you can modify it by updating or inserting nodes.

    Properties

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    Superelevation nodes of the curve, specified as an array of SuperElevationNode objects. By default, this property contains two nodes with Distance values of 0 and Length, where Length is the total length of the road.

    Superelevation spans of the specified SuperElevationCurve, specified as an array of SuperElevationSpan objects.

    Object Functions

    insertNodeInsert node in span sequence

    Examples

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    Create a roadrunner object, specifying the path to an existing project. For example, this code shows the path to a project, on a Windows® machine, located at "C:\RR\MyProject". This code assumes that RoadRunner is installed in the default location, and returns an object, rrApp, that provides functions for performing basic tasks such as opening, closing, and saving scenes and projects. 

    rrApp = roadrunner(ProjectFolder="C:\RR\MyProject");
    Create a new scene in RoadRunner by using the newScene function, specifying the roadrunner object rrApp. 
    newScene(rrApp)

    Create a RoadRunner authoring API object, rrAPi, that references the object for the current RoadRunner instance rrApp. The rrApi object enables you to programmatically author scenes, such as by adding and modifying road and lane components, using MATLAB®.

    rrApi = roadrunnerAPI(rrApp);

    Extract the object for your scene from the Scene property of the authoring API object rrApi. The extracted Scene object enables you to specify the scene in which to add scene components, such as roads and lanes. 

    scn = rrApi.Scene;

    Extract the object for your RoadRunner project from the Project property of the authoring API object rrApi. The extracted Project object enables you to specify the project folder for the current RoadRunner session from which to retrieve asset objects. You can use the asset objects to add lane markings to the lanes in your scene.

    prj = rrApi.Project;

    Use the addClothoidFitRoad function to add a new road. Specify the position of the road by specifying the positions of its start point startPt and end point endPt.

    startPt = [0 0 0];
endPt = [50 0 0];
rrRoad = addClothoidFitRoad(scn,[startPt; endPt]);

    Extract the reference lane from the ReferenceLane property of the road rrRoad. The extracted property ReferenceLane defines the center line of the road.

    refLane = rrRoad.ReferenceLane;

    Use the extracted refLane object to add lanes on either side of the reference lane of the road using the addLaneToLeft and addLaneToRight functions.

    leftLane = addLaneToLeft(refLane);
rightLane = addLaneToRight(refLane);

    Use the getAsset function to retrieve the LaneMarkingStyle objects for a dashed solid yellow lane marking. These objects define the lane marking assets used to mark the spans in the lane marking profile of the reference lane.

    dashedWhiteMarkingStyle = prj.getAsset("<PROJECT>/Assets/Markings/DashedSingleWhite.rrlms","LaneMarkingStyle");
solidWhiteMarkingStyle = prj.getAsset("<PROJECT>/Assets/Markings/SolidSingleWhite.rrlms","LaneMarkingStyle");

    Mark the boundaries of the lanes.

    leftLaneSpan = leftLane.LaneMarkingProfile.Spans(1);
leftLaneSpan.LaneMarkingStyle = solidWhiteMarkingStyle;
rightLaneSpan = rightLane.LaneMarkingProfile.Spans(1);
rightLaneSpan.LaneMarkingStyle = solidWhiteMarkingStyle;
referenceLaneSpan = refLane.LaneMarkingProfile.Spans(1);
referenceLaneSpan.LaneMarkingStyle = dashedWhiteMarkingStyle;

    RoadRunner scene canvas showing the creation of road

    Access the superelevation definition of the road by extracting its SuperElevationCurve property.

    seCurve = rrRoad.SuperElevationCurve;

    Inspect the default superelevation nodes of the road. By default, the SuperElevationCurve contains two nodes: one at the start of the road and one at the end of the road.

    nodes = seCurve.Nodes

    Apply Uniform Banking Along Entire Road

    Set the same banking angle at the start and end nodes to apply uniform banking along the full road length.

    nodes(1).Angle = 10;
nodes(end).Angle = 10;

    RoadRunner scene canvas showing the uniform banking along the entire road

    Define Non-Uniform Banking Using Start and End Nodes

    Assign different banking angles at the start and end of the road to create a continuous banking transition.

    nodes(1).Angle = 15;
nodes(end).Angle = -15;

    RoadRunner scene canvas showing non-uniform banking at the start and end of the road

    You can also use the addSuperElevation function to define different banking angles at the start and end of the road.

    addSuperElevation(rrRoad,0,15)   % 0 indicates the start position of the road
addSuperElevation(rrRoad,50,-15) % 50 indicates the end position of the road

    Insert Intermediate Superelevation Nodes

    Insert a new superelevation control point at a specified distance along the road.

    midNode = insertNode(seCurve,25);
midNode.Angle = -10;

    Insert another superelevation node between the start node and your new midpoint node.

    addSuperElevation(rrRoad,12,-10);

    RoadRunner scene canvas showing the new node inserted at the specified distance

    Modify Existing Superelevation Node

    Update the banking angle of an existing node without inserting a new one.

    midNode.Angle = 20;
    RoadRunner recalculates the banking profile of the road automatically.

    RoadRunner scene canvas showing the modification of an existing node

    Version History

    Introduced in R2026a

    See Also

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