12.9 Junction reference line

Junction reference lines are geometric references related to junctions. A junction reference line is defined in the reference line coordinate system. A junction reference line attaches the <elevationGrid> element and other relevant objects to the junction, for example traffic islands or potholes. A junction reference line has no lanes and no elevation or superelevation.

img
Figure 95. Junction reference line ~red arrow~

Figure 95 shows a junction and a junction reference line.

In ASAM OpenDRIVE, junction reference lines are represented by the <planView> element within the <junction> element.

UML class: t_road_planView
XML tag:   <planView> (Multiplicity: 1)

Contains geometry elements that define the layout of the road reference line in the x/y-plane (plan view).

<geometry> element

In ASAM OpenDRIVE, the geometry of a junction reference line is represented by the <geometry> element within the <planView> element.

UML class: t_road_planView_geometry
XML tag:   <geometry> (Multiplicity: 1..*)
Table 76. Attributes of the <geometry> element
Name Type Use Unit Description

hdg

double

required

rad

Start orientation (inertial heading)

length

t_grZero

required

m

Length of the element’s reference line

s

t_grEqZero

required

m

s-coordinate of start position

x

double

required

m

Start position (x inertial)

y

double

required

m

Start position (y inertial)

The <planView> element contains one <geometry> element with the <line> element.

XML example

<junction id="15">
    <planView>
        <geometry s="0.0000000000000000e+00"
                  x="3.0505642010572856e+01"
                  y="3.6353713565101820e+01"
                  hdg="2.9842438203363086e-01"
                  length="7.5257400000000004e+01">
            <line/>
        </geometry>
    </planView>
    <object type="roadSurface" subtype="pothole" name="" id="1" s="3.1064163564293011e+01" t="1.6886219784199805e+00" zOffset="0.0000000000000000e+00" validLength="0.0000000000000000e+00" orientation="none" length="0.3179999999999999e+00" width="0.4229999999999999e+00" height="0.0000000000000000e+00" hdg="5.7401170550235827e+00" pitch="0.0000000000000000e+00" roll="0.0000000000000000e+00">
        <surface>
          <CRG file="pothole.crg" hideRoadSurfaceCRG="true" zScale="1"/>
        </surface>
      </object>
</junction>

Rules

The following rules apply to junction reference lines:

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