Lane Division - woven-planet/opensafety-mbse GitHub Wiki
A linear, longitudinal designation inside of a Road Segment and roughly parallel with its edges for the purposes of separating Lanes of various types is a Lane Division. The inner and outer boundaries of any given Lane are established by two surrounding Lane Divisions.
We equate Lane Divisions with painted lines or curb edges most of the time, though there are many other physical features of the driving environment that may be construed to form a Lane Division. This is especially true when inclement weather or other adverse conditions are present. Degraded pavement conditions, weather, construction and other visual impediments may obscure or completely hide lane markings. Nonetheless, drivers (both human and automated) are often able to divine an effective Lane Division with cues such as map information, visible traffic patterns and color contrasts detected in the road surface.
The far edge of the Road Segment, say where pavement becomes gravel, or where the gravel drops off may constitute a Lane Division. This makes it possible to define the edge of a Shoulder Lane, for example.
Paint color, continuation patterns, stripe width and doubling, reflectors, construction cones and other physical elements may be combined to convey separation, intrusion and passing rules. Much of this visual symbology is region specific. In the future, much of this information may also be signaled in ways that are non-visual and readable only by computers.
To further complicate matters, a painted lane stripe may be visible yet not be observed by traffic due to overriding conditions such as construction, police activity, a more recent and brighter superseding stripe or other reasons.
The recognition and interpretation of lane symbols is outside the scope of our domain. Here we concern ourselves only with the existence and final interpreted meaning of a Lane Division and not its physical manifestation. If a line of construction cones is interpreted as a no-passing two way traffic separator, this becomes a Lane Division just as if it were a yellow stripe.
- ID + Road segment
Traffic on each side of this division flows in opposite directions.
Type: Boolean
A Lane Division may temporarily override any other existing markings. This could be the case with traffic cones or some other non-permanent barrier.
Type: Boolean
The distance between the left and right sides of a stripe or other Lane Division designation. This can be anything from zero for an invisible division to 30 cm or so. The width may become significant when a Lane Division is adjacent to a hard Median. If it becomes necessary for the Ego Vehicle to swerve to avoid an obstacle, we can take into account the distance between the innermost edge of the visible Lane Division to the hard boundary of the Median with an eye toward avoiding both, but knowing that there is some leeway for some intrusion. And it may be helpful to know how much space is marked in between Lanes as well for maneuvering purposes.
Type: Stripe Width 0..100 cm
This is the lateral distance away from the outermost Lane Division. The outermost Lane Division is always at 0.0 m with increasing distances moving toward the inside. The distance between any two adjacent Lane Divisions in the same Conduit defines the width of a Lane.
Type: Distance