Crowd Flow Observed

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

An observation related to the movement of people at a certain place and time.

Data Model

The data model is defined as shown below:

id: Entity ID.
- It shall be urn:ngsi-ld:CrowdFlowObserved:<identifier> being identifier a unique identifier.
type: Entity type.
- It shall be equal to CrowdFlowObserved.
dataProvider : Specifies the URL to information about the provider of this information
- Attribute type: Property. URL
- Optional
dateCreated : Entity's creation timestamp. (createdAt in NGSI-LD)
- Attribute type: Property. DateTime
- Read-Only. Automatically generated.
dateModified : Last update timestamp of this Entity. (modifiedAt in NGSI-LD)
- Attribute type: Property. DateTime
- Read-Only. Automatically generated.
source : A sequence of characters giving the original source of the Entity data as a URL.
- Attribute type: Property. URL
- Mandatory
location : Location of this crowd flow observation represented by a GeoJSON geometry.
- Attribute type: geo:json. (GeoProperty)
- Normative References: https://tools.ietf.org/html/rfc7946
- Mandatory if refRoadSegment or address are not present.
address : Civic address of this crowd flow observation.
- Attribute type: Property. Address
- Normative References: https://schema.org/address
- Mandatory if location or refRoadSegment are not present.
refRoadSegment : Concerned road segment on which the observation has been mede.
- Attribute type: Relationship. Reference to an entity of type RoadSegment.
- Mandatory if location or address are not present.
dateObserved : The date and time of this observation in ISO8601 UTC format. It can be represented by an specific time instant or by an ISO8601 interval. As a workaround for the lack of support of Orion Context Broker for datetime intervals, it can be used two separate attributes: dateObservedFrom, dateObservedTo.
- Attribute type: GeoProperty. DateTime or an ISO8601 interval represented as Text.
- Mandatory
dateObservedFrom : Observation period start date and time. See dateObserved.
- Attribute type: TemporalProperty. DateTime.
- Optional
dateObservedTo : Observation period end date and time. See dateObserved.
- Attribute type: TemporalProperty. DateTime.
- Optional
name : Name given to this observation.
- Attribute type: Property. Text.
- Normative References: https://uri.etsi.org/ngsi-ld/name equivalent to name
- Optional
description : Description of this observation.
- Normative References: https://schema.org/description
- Optional
peopleCount : Total number of people detected during this observation period.
- Attribute type: Property. Number. Positive integer.
- Optional
occupancy : Fraction of the observation time where a person has been occupying the observed walkway.
- Attribute type: Property. Number between 0 and 1.
- Optional
averageCrowdSpeed : Average speed of the crowd transiting during the observation period.
- Attribute type: Property. Number
- Default unit: Kilometer per hour (Km/h).
- Optional
congested : Flags whether there was a crowd congestion during the observation period in the referred walkway. The absence of this attribute means no crowd congestion.
- Attribute type: Property. Boolean
- Optional
averageHeadwayTime : Average headway time. Headway time is the time elapsed between two consecutive persons.
- Attribute type: Property. Number
- Default unit: second (s)
- Optional
direction : Usual direction of travel in the walkway referred by this observation with respect to the city center.
- Attribute type: Property. Text
- Allowed values: (inbound, outbound).
- Optional

Examples

Normalized Example

Normalized NGSI response

{
    "id": "urn:ngsi-ld:CrowdFlowObserved:Valladolid_1",
    "type": "CrowdFlowObserved",
    "dateObserved": {
        "value": "2018-08-07T11:10:00/2018-08-07T11:15:00"
    },
    "direction": {
        "value": "inbound"
    },
    "dateObservedFrom": {
        "type": "DateTime",
        "value": "2018-08-07T11:10:00Z"
    },
    "peopleCount": {
        "value": 100
    },
    "averageHeadwayTime": {
        "value": 5
    },
    "dateObservedTo": {
        "type": "DateTime",
        "value": "2018-08-07T11:15:00Z"
    },
    "location": {
        "type": "geo:json",
        "value": {
            "type": "LineString",
            "coordinates": [
                [-4.73735395519672, 41.6538181849672],
                [-4.73414858659993, 41.6600594193478],
                [-4.73447575302641, 41.659585195093]
            ]
        }
    },
    "congested": {
        "value": false
    }
}

key-value pairs Example

Sample uses simplified representation for data consumers ?options=keyValues

{
    "id": "urn:ngsi-ld:CrowdFlowObserved:Valladolid_1",
    "type": "CrowdFlowObserved",
    "dateObservedFrom": "2018-08-07T11:10:00",
    "dateObservedTo": "2018-08-07T11:15:00",
    "peopleCount": 100,
    "averageHeadwayTime": 5,
    "congested": false,
    "direction": "inbound",
    "location": {
        "type": "LineString",
        "coordinates": [
            [-4.73735395519672, 41.6538181849672],
            [-4.73414858659993, 41.6600594193478],
            [-4.73447575302641, 41.659585195093]
        ]
    }
}

LD Example

Sample uses the NGSI-LD representation

{
    "id": "urn:ngsi-ld:CrowdFlowObserved:Valladolid_1",
    "type": "CrowdFlowObserved",
    "dateObserved": {
        "type": "Property",
        "value": "2018-08-07T11:10:00/2018-08-07T11:15:00"
    },
    "direction": {
        "type": "Property",
        "value": "inbound"
    },
    "dateObservedFrom": {
        "type": "Property",
        "value": {
            "@type": "DateTime",
            "@value": "2018-08-07T11:10:00Z"
        }
    },
    "peopleCount": {
        "type": "Property",
        "value": 100
    },
    "averageHeadwayTime": {
        "type": "Property",
        "value": 5
    },
    "dateObservedTo": {
        "type": "Property",
        "value": {
            "@type": "DateTime",
            "@value": "2018-08-07T11:15:00Z"
        }
    },
    "location": {
        "type": "GeoProperty",
        "value": {
            "type": "LineString",
            "coordinates": [
                [-4.73735395519672, 41.6538181849672],
                [-4.73414858659993, 41.6600594193478],
                [-4.73447575302641, 41.659585195093]
            ]
        }
    },
    "congested": {
        "type": "Property",
        "value": false
    },
    "@context": [
        "https://schema.lab.fiware.org/ld/context",
        "https://uri.etsi.org/ngsi-ld/v1/ngsi-ld-core-context.jsonld"
    ]
}