Go to CAV-TEC V2.0 Data Types

Definition
Functional Requirements
Syntax
Semantics
Conformance
Performance

1 Definition

Road State is a Data Type describing the current physical, environmental, geometric, and traffic‑related conditions of a specific road segment. It provides the information required by MPAI‑CAV components to assess the state of the infrastructure relevant to perception, prediction, and decision‑making.

2 Functional Requirements

Road State shall satisfy the following requirements:

  • Identification – Road State shall identify the CAV producing the information and the road segment to which the state applies.
  • Temporal validity – Road State shall specify the time of creation and the validity interval of the described state.
  • Road attributes – Road State shall provide static or slowly varying attributes of the road segment.
  • Surface condition – Road State shall describe the current condition of the road surface, including wetness, snow, ice, contaminants, and confidence.
  • Weather conditions – Road State shall reference weather information relevant to driving, including temperature, humidity, precipitation, wind, fog, and ice.
  • Hazards – Road State shall describe hazards present on or near the road segment, including type, location, severity, spatial extent, recommended action, and confidence.
  • Dynamic road geometry – Road State shall represent temporary changes to road geometry, such as lane closures, temporary lane boundaries, temporary curvature, speed limits, and signage.
  • Traffic conditions – Road State shall describe traffic flow and traffic jams affecting the road segment.
  • Cooperative perception – Road State shall represent information obtained from cooperative perception sources, including shared objects, occupancy grids, free‑space maps, and predicted trajectories.
  • Fusion metadata – Road State shall describe the fusion of multiple sources, including source list, fusion method, conflict resolution strategy, and overall confidence.
  • Predictions – Road State shall provide predictions of the evolution of traffic, weather, and hazards over time.
  • Metadata and traceability – Road State shall include MPAI‑PTF Data Exchange Metadata to support data exchange, logging, and interpretation.

3 Syntax

https://schemas.mpai.community/CAV2/V2.0/data/RoadState.json

4 Semantics

Table 1 specifies the semantics of the Road State Data Type.

Table 1 – Semantics of the Road State Data Type

Label Type Req. Description
Header string (CAV-RDS-V2.0) Yes Road State Header – Standard CAV-RDS-Vx.y
MInstanceID string Identifier of the M-Instance (Virtual Space) associated with this Road State.
UEnvironmentID string Identifier of the U-Environment (Real Space) associated with this Road State.
RoadStateID string Yes Unique identifier of this Road State instance.
RoadStateTime Simple Time Yes Time this Road State was produced.
RoadStateSpaceTime Simple Time Space/Time where/when this Road State applies.
CAVID string Yes Identifier of the CAV producing this Road State.
Segment Road Segment ID Yes Identifier of the road segment to which this Road State applies: a Road and a Segment Number in it.
RoadAttributes object Yes Static or slowly varying attributes of the road segment.
RoadAttributes.Lanes integer Number of lanes on the road segment.
RoadAttributes.SurfaceType string Type of road surface (e.g., asphalt, concrete, gravel).
RoadAttributes.Curvature number Curvature of the road segment (1/m).
RoadAttributes.Slope number Longitudinal slope of the road segment (degrees or %).
SurfaceCondition object Current condition of the road surface.
SurfaceCondition.WetnessLevel number Wetness level of the road surface [0..1].
SurfaceCondition.SnowDepth number Depth of snow on the road surface (cm).
SurfaceCondition.IcePresence boolean Indicates whether ice is present on the road surface.
SurfaceCondition.FrictionCoefficientEstimate number Estimated friction coefficient of the road surface [0..1].
SurfaceCondition.OilOrContaminantPresence boolean Indicates the presence of oil or other contaminants on the road surface.
SurfaceCondition.Confidence number Confidence in the surface condition estimate [0..1].
WeatherData Weather Data Weather information relevant to driving.
Hazard[] object [] Hazards present on or near the road segment.
Hazard[].HazardType string Yes Type of hazard. One of: pothole, debris, animal, fallen_tree, flooding, obstruction, ice_patch, other.
Hazard[].Location Point Of View Yes Location of the hazard.
Hazard[].Severity integer Severity level of the hazard [0..3].
Hazard[].SpatialExtent number Spatial extent of the hazard (metres).
Hazard[].RecommendedAction string Recommended action for the CAV. One of: slow, avoid, reroute, none.
Hazard[].Confidence number Confidence in the hazard estimate [0..1].
DynamicRoadGeometry object Temporary modifications to the road geometry.
DynamicRoadGeometry.TemporaryLaneBoundaries array [] Temporary lane boundary polylines.
DynamicRoadGeometry.LaneClosures string [] Identifiers of closed lanes.
DynamicRoadGeometry.TemporaryCurvature number Temporary curvature of the road segment (1/m).
DynamicRoadGeometry.TemporarySpeedLimits number Temporary speed limit in effect (km/h).
DynamicRoadGeometry.TemporarySignage[] object [] Temporary road signs present on the segment.
DynamicRoadGeometry.TemporarySignage[].Type string Type of road sign.
DynamicRoadGeometry.TemporarySignage[].Location Point Of View Location of the road sign.
TrafficFlow object Traffic flow information for the road segment.
TrafficFlow.FlowPerLane number [] Vehicle flow per lane (vehicles/hour).
TrafficFlow.MeanSpeedPerLane number [] Mean vehicle speed per lane (km/h).
TrafficFlow.VehicleClassDistribution object Distribution of vehicle classes as proportions.
TrafficFlow.StopAndGoOscillationIndex number Stop-and-go oscillation index [0..1].
TrafficFlow.Confidence number Confidence in the traffic flow estimate [0..1].
TrafficJam object Traffic jam information for the road segment.
TrafficJam.Location Point Of View [] Spatial extent of the traffic jam as a polyline.
TrafficJam.Length number Length of the traffic jam (metres).
TrafficJam.Severity integer Severity of the traffic jam [0..3].
TrafficJam.EstimatedDelay number Estimated delay caused by the traffic jam (seconds).
TrafficJam.Confidence number Confidence in the traffic jam estimate [0..1].
CooperativePerception object Information obtained from cooperative perception sources.
CooperativePerception.SharedObjectList[] object [] Objects detected and shared by cooperative sources.
CooperativePerception.SharedObjectList[].ID string Identifier of the detected object.
CooperativePerception.SharedObjectList[].Class string Classification of the detected object.
CooperativePerception.SharedObjectList[].Pose Point Of View Pose of the detected object.
CooperativePerception.SharedObjectList[].Velocity number Velocity of the detected object (m/s).
CooperativePerception.SharedOccupancyGrid object Shared occupancy grid from cooperative sources.
CooperativePerception.SharedOccupancyGrid.Resolution number Grid cell resolution (metres/cell).
CooperativePerception.SharedOccupancyGrid.Width integer Number of columns in the grid.
CooperativePerception.SharedOccupancyGrid.Height integer Number of rows in the grid.
CooperativePerception.SharedOccupancyGrid.Data number [] Grid cell values, row-major order.
CooperativePerception.SharedFreeSpaceMap object Shared free-space map from cooperative sources.
CooperativePerception.SharedFreeSpaceMap.Resolution number Grid cell resolution (metres/cell).
CooperativePerception.SharedFreeSpaceMap.Width integer Number of columns in the grid.
CooperativePerception.SharedFreeSpaceMap.Height integer Number of rows in the grid.
CooperativePerception.SharedFreeSpaceMap.Data number [] Grid cell values, row-major order.
CooperativePerception.SharedPredictedTrajectories object [] Predicted trajectories shared by cooperative sources.
CooperativePerception.SourceList string [] Identifiers of cooperative perception sources.
FusionMetadata object Information describing the fusion of multiple sources.
FusionMetadata.SourceCount integer Number of sources fused.
FusionMetadata.SourceIDs string [] Identifiers of the fused sources.
FusionMetadata.FusionMethod string Method used for fusion.
FusionMetadata.ConflictResolutionStrategy string Strategy used to resolve conflicts between sources.
FusionMetadata.OverallConfidence number Overall confidence in the fused result [0..1].
Predictions object Predicted evolution of traffic, weather, and hazards.
Predictions.TrafficFlowForecast[] object [] Forecasted traffic flow states, each with the fields of Traffic Flow.
Predictions.WeatherEvolution Weather Data [] Forecasted weather evolution.
Predictions.HazardPropagation[] object [] Predicted hazard propagation, each with the fields of Hazard.
DataXMData Data Exchange Metadata MPAI-PTF Data Exchange Metadata providing provenance, authorisation, legal, security, and confidence information associated with this Road State in a trusted data exchange context.
DescrMetadata string Human-readable descriptive metadata of the Road State (plain text, max 2048 characters).

5 Conformance Testing

Data conform to the Road State Data Type when they validate against its schema. If the schema references other schemas, data referencing a secondary schema shall also validate against that schema, if present, and conform with the Qualifier, if present.

6 Performance Assessment