DATEX II MST Traffic Data Interface methodology

The DATEX II MST Traffic Data Interface is based on two main phases:

  1. Anagraphic data load, contained in the file measurement_current.xml.
  2. Traffic data load, contained in the file trafficspeed.xml.

Important:  No specific assumptions can be made about the provisioning process that provide you these XML files.

The XML files involved can be downloaded here.

You can download:

  1. measurement_current.xml.gz
  2. trafficspeed.xml.gz

The first phase is based on some necessary configuration steps (see → DATEX II MST Traffic Data Interface configuration).

This phase is based on a API endpoint that loads data through the file:

measurement_current.xml.gz

This file is used as payload of the request.

POST datex2import/optima/measureTable

Example of request:

https://<OPTIMA_HOST_IP_ADDRESS>:<PORT_NUMBER>/datex2import/optima/measureTable

Response status

HTTP status Description

200 OK

Result of the processed request.

400 Bad request

The request does not contain the payload ( file measurement_current.xml.gz).

The outcome of this operation is to fill the DATEX2_MEASUREMENT_SITE_TABLE.

According to the fragment of file indicate in → Example of measurement_current.xml, we must have in the DB (see → DATEX II MST Traffic Data Interface configuration):

  • a count location with name PZH01_MST_0687_01
  • a detector with name lane1

  • a VEHICLE_CLASS_TSYS table with a data record set through the query:

    INSERT INTO vehicle_class_tsys (lmin, lmax, vehicle_type, tsys) VALUES (NULL, 5.600000, '', 'CAR_TO_PCU_Traffic_Data');

The result is a data record in DATEX2_MEASUREMENT_SITE_TABLE:

Field Value

table_id

NDW01_MT

table_version

1135

publication_time

 

site_id

PZH01_MST_0687_01

site_version

8

site_name

N450 km 2.735

version_time

 

Nlane

1

Indx

1

Accuracy

95

period

60

lane

lane1

vehicle_class_tsys

1

value_type

traffic_flow

Important:  Before to load traffic data, is necessary to create the DB tables TRAFFICSTATE_DATEX2 and TRAFFICSTATE_DATEX2_RLTM (see → Traffic states and real-time traffic states – TRAFFICSTATE table, TRAFFICSTATE_RLTM table).

This phase is based on a API endpoint that loads data through the file:

trafficspeed.xml.gz.

POST datex2import/optima/MeasurementsZip

Example of request:

https://<OPTIMA_HOST_IP_ADDRESS>:<PORT_NUMBER>/datex2import/optima/MeasurementsZip

Response status

HTTP status Description

200 OK

Result of the processed request.

400 Bad request

The request does not contain the payload ( file trafficspeed.xml.gz).

In order to successfully load traffic data it’s necessary the matching of the id and version attributes of the tags:

measurement_current.xml trafficspeed.xml

<measurementSiteRecord> tag

  • id="PZH01_MST_0687_01"
  • version="8"

<measurementSiteReference> tag

  • id="PZH01_MST_0687_01"
  • version="8"

If this matching fails, the data record is not loaded.

<measurementSiteTable id="NDW01_MT" version="1135">
    <measurementSiteRecord id="PZH01_MST_0687_01" version="8">
        <measurementSiteRecordVersionTime>2019-08-30T00:14:07Z</measurementSiteRecordVersionTime>
        <computationMethod>arithmeticAverageOfSamplesInATimePeriod</computationMethod>
        <measurementEquipmentReference>0687_01</measurementEquipmentReference>
        <measurementEquipmentTypeUsed>
            <values>
                <value lang="nl">lus</value>
            </values>
        </measurementEquipmentTypeUsed>
        <measurementSiteName>
            <values>
                <value lang="nl">N450 km 2.735</value>
            </values>
        </measurementSiteName>
        <measurementSiteNumberOfLanes>1</measurementSiteNumberOfLanes>
        <measurementSide>northEastBound</measurementSide>
        <measurementSpecificCharacteristics index="1">
            <measurementSpecificCharacteristics>
                <accuracy>95</accuracy>
                <period>60</period>
                <specificLane>lane1</specificLane>
                <specificMeasurementValueType>trafficFlow</specificMeasurementValueType>
                <specificVehicleCharacteristics>
                    <lengthCharacteristic>
                        <comparisonOperator>lessThan</comparisonOperator>
                        <vehicleLength>5.6</vehicleLength>
                    </lengthCharacteristic>
                </specificVehicleCharacteristics>
            </measurementSpecificCharacteristics>
........
....
<siteMeasurements
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <measurementSiteReference id="PZH01_MST_0687_01" version="8" targetClass="MeasurementSiteRecord"/>
    <measurementTimeDefault>2019-10-25T13:23:00Z</measurementTimeDefault>
    <measuredValue index="1">
        <measuredValue>
            <basicData xsi:type="TrafficFlow">
                <vehicleFlow>
                    <vehicleFlowRate>360</vehicleFlowRate>
                </vehicleFlow>
            </basicData>
        </measuredValue>
    </measuredValue>
....
    <measuredValue index="5">
        <measuredValue>
            <basicData xsi:type="TrafficSpeed">
                <averageVehicleSpeed numberOfInputValuesUsed="6" standardDeviation="8.77">
                    <speed>65</speed>
                </averageVehicleSpeed>
            </basicData>
        </measuredValue>
    </measuredValue>
</siteMeasurements>