Lane Boundary Attributes Model
In the Lane Model, Lane Boundaries can bear the following types of attributes:
- Lane Boundary Markings
- Lane Boundary Marking Style
- Lane Boundary Marking Color
- Road Boundary Type
- Lane Boundary Traversal
- Lane Boundary Center Divider Indicator
The Protocol Buffer schema and values for these attributes are documented in Lane Boundary Attributes
Lane Boundary Markings
Topology Reference Type: Lane Boundary Parametric Range
Format Reference: LaneBoundaryMarking
Description: Lane Boundary Markings define the visible characteristics of a Lane Boundary, so these markings that run longitudinally between or beside lanes. Markings that are within or across lanes (such as arrows, icons, and text) are defined separately.
Elements:
- Number of Marking Elements: The "element_number" parameter, which is repeated, determines the number of side-by-side components in the relevant Lane Marking. (Note: A "0" value indicates no markings on the designated range of the Lane Boundary.)
- Marking Alignment: Where applicable, Marking Alignment indicates how the boundary marking elements are aligned laterally with the boundary geometry. If unspecified, the overall lane marking is assumed to be centered laterally over the Lane Boundary. The Marking Alignment parameter allows a finer description of the lateral placement, with any individual marking element's center or edge designated as lying on the Lane Boundary. (Note: This parameter is not applicable when element_number = 0.)
- Group Relative Position: This parameter indicates which of the marking elements is referred to in the alignment. (Note: The value of this parameter cannot exceed the Number of Marking Elements.)
- Element Relative Position:
- Aligned to midpoint
- Aligned to left edge
- Aligned to right edge
- Unknown
- Group Relative Position: This parameter indicates which of the marking elements is referred to in the alignment. (Note: The value of this parameter cannot exceed the Number of Marking Elements.)
- Marking Element Details: Marking Element Details are ordered left-to-right with respect to the digitized direction of the Lane Boundary curve. For each Marking Element in order, we describe the details on Style and Color (see below). Note: This parameter is not applicable when the Number of Marking Elements is 0.
- Marking Element Style:
See below for details.
- Marking Element Color
See below for details.
- Marking Element Style:
Lane Boundary Marking Style
Topology Reference Type: Lane Boundary Parametric Range
Format Reference: LaneBoundaryMarking
Description: This attribute represents the style that makes up the visible boundary of the lane.
Values:
- LANE_BOUNDARY_MARKING_STYLE_UNKNOWN
- SOLID
- DASHED
- ALTERNATE_DASHED
Lane Boundary Marking Color
Topology Reference Type: Lane Boundary Parametric Range
Format Reference: LaneBoundaryMarking
Description: Lane Boundary Marking Color is important for lane guidance, path planning, and localization. The color of a Lane Boundary Marking Element is applied to the map to signify the color of the visible boundary of the lane. A single Lane Boundary Marking can comprise multiple elements with different colors.
Values:
- LANE_BOUNDARY_MARKING_COLOR_UNKNOWN
- WHITE
- YELLOW
Road Boundary Type
Topology Reference Type: Lane Boundary Parametric Range
Format Reference: RoadBoundaryType
Description: Defines the Road boundary type attribution that references a lane boundary.
Elements:
- RoadBoundaryTypeValue: The type of road boundary.
- ROAD_BOUNDARY_TYPE_UNKNOWN
- GORE
- UNMARKED_EDGE_OF_ROAD_SURFACE
- CURB
- RoadBoundaryDerivationDetails: Additional information used during the derivation process of the road boundary attribution.
Lane Boundary Traversal
Topology Reference Type: Lane Boundary Parametric Range
Format Reference: Lane Boundary Traversal
Description: This attribute describes whether traffic is legally restricted to move laterally into a legally available adjacent lane, in either or both directions.
This attribute of the Lane Feature is required only when the adjacent lane is available for use: it indicates if this is a location where a lateral lane change is not allowed. For example, a HOV lane may be adjacent to a general traffic lane. At some locations, boundary markings indicate that lane change is prohibited; at other locations, boundary markings indicate that lane change is allowed. Vehicles that qualify to use the HOV lane may make the lane change only at those places where traversal is allowed. No vehicles (even HOV-qualified vehicles) are allowed to change lanes at the places where traversal is not allowed, and non-HOVs are prohibited from the lane everywhere.
Lane Traversal is not used to indicate that the adjacent lane is unavailable for use; the latter is indicated by attributes on the adjacent lane, such as travel direction, lane type or access characteristics.
Lane Boundary Center Divider Indicator
Topology Reference Type: Lane Boundary Parametric Range
Format Reference: Lane Boundary Center Divider Indicator
Description: This feature indicates that the lane boundary marking divides lanes between opposing travel directions on bidirectional links. It is an indication that a lane boundary serves as a center divider.
