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

  • 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 metadata and trace information to support data exchange, logging, and interpretation.

3   Syntax

https://schemas.mpai.community/CAV2/V1.1/data/RoadState.json

4   Semantics

Label Definition
Header Road State Header – Standard “CAV-RDS-Vx.y”
RoadStateTime Time of creation and validity of the Road State.
CAVID Identifier of the CAV producing the Road State.
Segment Identifier of the road segment to which the Road State applies.
RoadAttributes Static or slowly varying attributes of the road segment.
SurfaceCondition Description of the current road surface condition.
WeatherData Weather information relevant to driving.
Hazard Hazards present on or near the road segment.
DynamicRoadGeometry Temporary modifications to the road geometry.
TrafficFlow Traffic flow information for the road segment.
TrafficJam Traffic jam information for the road segment.
CooperativePerception Information obtained from cooperative perception sources.
FusionMetadata Information describing the fusion of multiple sources.
Predictions Predicted evolution of traffic, weather, and hazards.
DataExchangeMetadata Metadata related to data exchange.
Trace Trace information for logging and processing history.
DescrMetadata Descriptive metadata associated with the Road State instance.