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SAE J2735-Draft-Rev28 [issued: 11-10-08]
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This is an SAE Motor Vehicle Council draft document of the DSRC committee, subject to change.
other in the intersection. Observe that the data structure of each is the same. These approaches then define
lanes with properties, each with a unique index value within this link object. The approach named and
number is an (optional) convenience assigned in this data structure for human users during testting. The
lane number is the key assignment used to map between this and other objects (such as the movement states
found in the SPAT message). The lane number and the intersection number, taken as a set, represent a
unique path of travel thought the link (which may be traversed by specific types of travelers, vehicles,
pedestrians, etc. as a function of the signal timing and regulatory environment then in place). It may also
contain additional information about the approach such as the road type classification and any barriers
which are present.
ASN.1 Representation:
ApproachObject ::= SEQUENCE {
refPoint ReferencePoint OPTIONAL,
-- optional reference from which subsequent
-- data points in this link are offset
laneWidth LaneWidth OPTIONAL,
-- reference width used by subsequent
-- lanes until a new width is given
approach Approach OPTIONAL,
-- list of Approaches and thier lanes
egress Approach OPTIONAL,
-- list of Egresses and thier lanes
...
}
XML Representation:
<xs:complexType name="ApproachObject" >
<xs:sequence>
<xs:element name="refPoint" type="ReferencePoint" minOccurs="0"/>
<!-- OPTIONAL reference from which subsequent
data points in this link are offset -->
<xs:element name="laneWidth" type="LaneWidth" minOccurs="0"/>
<!-- reference width used by subsequent
lanes until a new width is given -->
<xs:element name="approach" type="Approach" minOccurs="0"/>
<!-- list of Approaches and thier lanes -->
<xs:element name="egress" type="Approach" minOccurs="0"/>
<!-- list of Egresses and thier lanes -->
</xs:sequence>
</xs:complexType>
Used By: This entry is used directly by one other data structure in this standard, a DF called
DF_Intersection <ASN> <XML>. In addition, this item may be used by data structures in other ITS
standards.
Remarks: Note that the offset data found in the underlying data structures will use the values found in the
last ReferencePoint and the last NodeConfig as the basis to which the offset are added values. Normally
this will be found in the enclosing object (typically an intersection type) but it may be reestablished here if
needed (this is intended for use in the case of very large intersections which may exceed the offset ranges).
If present, it applies to the scope of this link object, and not to any subsequent link objects which may be
found in the same message. Similar logic is applied to the Node Configuration element, if present.
6.5 Data Frame: DF_BarrierLane
Use: A Barrier Lane data structure provides a unique lane number, as well as various details such as its
width and attributes and a path within an approach structure for different types of traffic barriers, medians,
and other roadways geometry and the like. The BarrierAttributes data element denotes what generally type
of Barrier that it is. The nodeList data element provides a detailed set of offset values to map the path of
the Barrier.
ASN.1 Representation:
BarrierLane ::= SEQUENCE {
laneNumber LaneNumber,