Road Segment

This repository is now archived and subsequent works will be carried out the in Smart data models repositories. The latest version of this Data Model can be found at https://github.com/smart-data-models/dataModel.Transportation**

Description

This entity contains a harmonised geographic and contextual description of a road segment. A collection of road segments are used to describe a Road.

Road segments can include several lanes. This data model allows to convey road segments made up of heterogeneous lanes (different in their usage, speed, height, etc.).

Lanes are identified by using integer numbers between 1 and n, being number 1 the lane to the right when going forwards. The forward direction is the direction denoted by the vector which goes from the segment's start point to the segment's endpoint. This is the same convention as the one used by OpenStreetMap.

This entity is primarily associated with the Automotive and Smart City vertical segments and related IoT applications.

This data model has been developed in cooperation with mobile operators and the GSMA.

Data Model

The data model is defined as shown below:

id : Unique identifier.
type : Entity type. It must be equal to RoadSegment.
dataProvider : Specifies the URL to information about the provider of this information
- Attribute type: Property. URL
- Optional
dateCreated : Entity's creation timestamp.
- Attribute type: Property. DateTime
- Read-Only. Automatically generated.
dateModified : Last update timestamp of this entity.
- Attribute type: Property. DateTime
- Read-Only. Automatically generated.
source : The source of this data.
- Attribute type: Property. URL
- Optional
name : Name given to this road segment.
- Attribute type: Property. Text.
- Normative References: https://uri.etsi.org/ngsi-ld/name equivalent to name
- Mandatory
alternateName : An alias for this road segment.
- Attribute type: Property. Text
- Normative References: https://schema.org/alternateName
- Optional
refRoad : Road to which this road segment belongs to.
- Attribute type: Property. A reference to an entity of type Road.
- Mandatory
location : A GeoJSON (multi)line string which defines this road segment.
- Attribute type: GeoProperty. geo:json.
- Normative References: https://tools.ietf.org/html/rfc7946
- Mandatory
startPoint : The start point of this road segment encoded as a GeoJSON point.
- Attribute type: Property. geo:json
- Normative References: https://tools.ietf.org/html/rfc7946
- Mandatory
endPoint : The endpoint of this road segment encoded as a GeoJSON point.
- Attribute type: Property. geo:json
- Normative References: https://tools.ietf.org/html/rfc7946
- Mandatory
startKilometer : The kilometer number (measured from the road's start point) where this road segmnent starts.
- Attribute type: Property. Number
- Optional
endKilometer : The kilometer number (measured from the road's start point) where this road segment ends.
- Attribute type: Property. Number
- Optional
allowedVehicleType : Vehicle type(s) allowed to transit through this road segment.
- Attribute type: Property. List of Text
- Allowed values: The following values defined by VehicleTypeEnum, DATEX 2 version 2.3: - (agriculturalVehicle, bicycle, bus, car, caravan, carWithCaravan, carWithTrailer, constructionOrMaintenanceVehicle, lorry, moped, motorcycle, motorcycleWithSideCar, motorscooter, tanker, trailer, van, anyVehicle)
- Mandatory
totalLaneNumber : Total number of lanes offered by this road segment.
- Attribute type: Property. Number. Integer greater than 0.
- Mandatory
length : Total length of this road segment in kilometers.
- Attribute type: Property. Number
- See also https://schema.org/length
- Default unit: Kilometer (Km)
- Optional
maximumAllowedSpeed : Maximum allowed speed while transiting this road segment. More restrictive limits might be applied to specific vehicle types (trucks, caravans, etc.).
- Attribute type: Property. Number
- Default unit: Kilometer per hour (Km/h).
- Optional
minimumAllowedSpeed : Minimum allowed speed while transiting this road segment.
- Attribute type: Property. Number
- Default unit: Kilometer per hour (Km/h).
- Optional
maximumAllowedHeight : Maximum allowed height for vehicles transiting this road segment.
- Attribute type: Property. Number
- See also: https://schema.org/height
- Default unit: Meter (m)
- Optional
maximumAllowedWeight : Maximum allowed weight for vehicles transiting this road segment.
- Attribute type: Property. Number
- See also: https://schema.org/weight
- Default unit: Kilogram (Kg)
- Optional
width : Road's segmwent width.
- Normative References: https://schema.org/width
- Default unit: Meter (m)
- Optional
laneUsage : This attribute can be used to convey specific parameters describing each lane.
- Attribute type: Property. List of Text
- Allowed values: It must contain a string per road segment lane. The element 0 of the array must contain the information of lane 1, and so on. Format of the referred string must be: "<lane_direction>, <lane_minimumAllowedSpeed>, <lane_maximumAllowedSpeed>, <lane_maximumAllowedHeight>, <lane_maximumAllowedWeight>" . <lane_direction> is a text string with the following allowed values:
  - forward. The lane is currently used in the forwards direction.
  - backward. The lane is currently used in the backwards direction. The only mandatory parameter is lane_direction. If not specified, the rest of parameters can be assumed to be equal to those specified at entity level.
- Optional
category : Allows to convey extra characteristics of a road segment.
- Attribute type: Property. List of Text
- Allowed values:
  - oneway : Flags whether the road segment can only be used in one direction. If not present it means road segment can be used in both directions (forwards and backwards). See also http://wiki.openstreetmap.org/wiki/Key:oneway
  - toll : Flags whether the road segment is under toll fees.
  - link : Flags whether this road segment is an auxiliary link segment for exiting or entering a road. See https://wiki.openstreetmap.org/wiki/Tag:highway%3Dmotorway_link
  - Any other value meaningful to an application.
- Optional

The properties laneUsage and those which convey the maximum allowed parameters can be dynamic, for instance, a lane direction can be temporarily changed to improve traffic conditions.

Note: JSON Schemas are intended to capture the data type and associated constraints of the different Attributes, regardless their final representation format in NGSI(v2, LD).

Examples

Normalized Example

Normalized NGSI response

{
    "id": "Spain-RoadSegment-A62-osm-24702186",
    "type": "RoadSegment",
    "category": {
        "value": "oneway"
    },
    "endPoint": {
        "value": {
            "type": "Point",
            "coordinates": [-4.55167335377909, 41.8570461783071]
        }
    },
    "name": {
        "value": "Valladolid-Due\u00f1as"
    },
    "startPoint": {
        "value": {
            "type": "Point",
            "coordinates": [-4.7299180606009, 41.6844918725019]
        }
    },
    "allowedVehicleType": {
        "value": ["car", "bus", "lorry", "trailer", "tanker", "van", "caravan"]
    },
    "source": {
        "value": "http://wwww.openstreetmap.org"
    },
    "totalLaneNumber": {
        "value": 2
    },
    "location": {
        "type": "geo:json",
        "value": {
            "type": "LineString",
            "coordinates": [
                [-4.7299180606009, 41.6844918725019],
                [-4.72855890957602, 41.6860596957855],
                [-4.5520357341647, 41.8569278186523],
                [-4.55167335377909, 41.8570461783071]
            ]
        }
    },
    "minimumAllowedSpeed": {
        "value": 60
    },
    "refRoad": {
        "type": "Relationship",
        "value": "Spain-Road-A62"
    },
    "maximumAllowedSpeed": {
        "value": 120
    },
    "laneUsage": {
        "value": ["forward", "forward"]
    }
}

key-value pairs Example

Sample uses simplified representation for data consumers ?options=keyValues

Please note that this road segment's line string has been simplified only four points just to make the example shorter.

{
    "id": "Spain-RoadSegment-A62-osm-24702186",
    "type": "RoadSegment",
    "name": "Valladolid-Dueñas",
    "category": "oneway",
    "refRoad": "Spain-Road-A62",
    "totalLaneNumber": 2,
    "maximumAllowedSpeed": 120,
    "minimumAllowedSpeed": 60,
    "startPoint": {
        "type": "Point",
        "coordinates": [-4.7299180606009, 41.6844918725019]
    },
    "endPoint": {
        "type": "Point",
        "coordinates": [-4.55167335377909, 41.8570461783071]
    },
    "allowedVehicleType": [
        "car",
        "bus",
        "lorry",
        "trailer",
        "tanker",
        "van",
        "caravan"
    ],
    "location": {
        "type": "LineString",
        "coordinates": [
            [-4.7299180606009, 41.6844918725019],
            [-4.72855890957602, 41.6860596957855],
            [-4.5520357341647, 41.8569278186523],
            [-4.55167335377909, 41.8570461783071]
        ]
    },
    "laneUsage": ["forward", "forward"],
    "source": "http://wwww.openstreetmap.org"
}

LD Example

Sample uses the NGSI-LD representation

{
    "id": "urn:ngsi-ld:RoadSegment:Spain-RoadSegment-A62-osm-24702186",
    "type": "RoadSegment",
    "category": {
        "type": "Property",
        "value": "oneway"
    },
    "endPoint": {
        "type": "Property",
        "value": {
            "type": "Point",
            "coordinates": [-4.55167335377909, 41.8570461783071]
        }
    },
    "name": {
        "type": "Property",
        "value": "Valladolid-Due\u00f1as"
    },
    "startPoint": {
        "type": "Property",
        "value": {
            "type": "Point",
            "coordinates": [-4.7299180606009, 41.6844918725019]
        }
    },
    "allowedVehicleType": {
        "type": "Property",
        "value": ["car", "bus", "lorry", "trailer", "tanker", "van", "caravan"]
    },
    "source": {
        "type": "Property",
        "value": "http://wwww.openstreetmap.org"
    },
    "totalLaneNumber": {
        "type": "Property",
        "value": 2
    },
    "location": {
        "type": "GeoProperty",
        "value": {
            "type": "LineString",
            "coordinates": [
                [-4.7299180606009, 41.6844918725019],
                [-4.72855890957602, 41.6860596957855],
                [-4.5520357341647, 41.8569278186523],
                [-4.55167335377909, 41.8570461783071]
            ]
        }
    },
    "minimumAllowedSpeed": {
        "type": "Property",
        "value": 60
    },
    "refRoad": {
        "type": "Relationship",
        "object": "urn:ngsi-ld:Road:Spain-Road-A62"
    },
    "maximumAllowedSpeed": {
        "type": "Property",
        "value": 120
    },
    "laneUsage": {
        "type": "Property",
        "value": ["forward", "forward"]
    },
    "@context": [
        "https://schema.lab.fiware.org/ld/context",
        "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context.jsonld"
    ]
}

Use it with a real service

T.B.D.