Low Level Function
3.1.1.14 Manage Urban Traffic Data

Overview

This Function shall be capable of providing the following facilities:

(1) The ability to manage the store of Inter-urban Traffic Data.
(2) The ability to collect data about traffic conditions (i.e. traffic flows, road segment use, journey times, etc.) in the urban road network and car park data from other functionality in the Manage Traffic Functional Area.
(3) The ability to receive data about traffic conditions (i.e. traffic flows, predicted road segment use (from trip plans), journey times, etc.) from functionality in the Provide Electronic Payment Facilities, Provide Support for Host Vehicle Systems and Provide Traveller Journey Assistance Functional Areas, plus the Cellular Communications Provider.
(4) The ability to collate and fuse all data that is collected and received, using the inter-urban road network static data as a mechanism for achieving this where necessary.
(5) The ability to exchange data collected by the Function with similar functionality in another instance of the System, through the Other Related System, Urban Traffic Management System.
(6) The ability to load the collated and fused data into the store of Urban Traffic Data in a coherent way that makes it easy to retrieve it for particular road segments, or larger parts of the urban road network.
(7) The ability to provide the collated and fused data from the store of Urban Traffic Data to other functionality in the Manage Traffic area, either for its own use, or for sending to functionality in other Functional Areas and to entities outside the System.
(8) The ability to provide current urban traffic data for use in creating short and medium term predictions for that data and when received to load that data into the store of Urban Traffic Data.

Functional Requirements

(a) continuously monitor for receipt of any of the input data flows
(b) when any of the data flows containing data about traffic using the urban road network is received, process the data, applying data fusion where the data relates to the same part of the road network
(c) use the data received in the urban static data for traffic conditions data flow to determine the location and characteristics of the part of the urban road network to which the received data applies
(d) convert the contents of data flow containing urban infrastructure usage data into actual traffic flows and apply it to the correct part(s) of the urban road network
(e) load the results of (b) to (d) into the store of Urban Traffic Data, to provide the current traffic flow data and fusing it with data already in the store to provide a coherent set of historic traffic data for the urban network
(f) also use the results of (b) to (d) to provide traffic data for other urban traffic management systems
(g) analyse the results of (b) to (d) to determine where traffic queues are present and from use successive collections of data to determine the speed of propagation of the tail end of the queue
(h) use the data received in the urban static data for traffic conditions data flow to determine the locations of the queues
(i) send the results of (g) and (h) to the output warnings to the driver in the vehicle functionality
(j) analyse the results of (b) to (d) to determine the current journey time for each segment of the urban road network store it in the store of Urban Traffic Data, fusing it with similar data already in the store to provide a historical record of journey times
(k) use the results of (b) to (d) to provide the output data flows containing current traffic data that shall be sent directly to other functionality and to the function for transmission to other entities and functionality in other functional areas
(l) periodically read the journey times from the store of Urban Traffic Data and use them to update the default urban road segment journey times using the default urban journey time update data flow
(m) when the urban data updates data flow is received in (a) from other urban traffic systems, store it in its own part of the store of Urban Traffic Data to provide a coherent historical record of urban traffic data in other relevant geographic areas
(n) when the inter-urban to urban traffic data transfer data flow is received in (a), store it in its own part of the store of Urban Traffic Data to provide a coherent historical record of inter-urban traffic data in relevant areas
(o) when the data flow containing urban traffic predicted data is received in (a), store it in its own part of the store of Urban Traffic Data and delete any data that is no longer predicted, i.e. the time for which it is predicted in now current or in the past
(p) when either of the data flows containing car park data is received in (a) store their contents in the car park part of the store of Urban Traffic Data to provide a coherent historical record of car park use
(q) when the data flow containing journey times from a cellular communications network provider is received, filter the data to remove travel times that are not between locations in the urban road network, e.g. for pedestrian routes and the inter-urban road network and check for consistency, i.e. does it fit with other data for road vehicles, or is it perhaps a cyclist
(r) add the data that does pass the tests in (q) to the store of journey times in the store of Urban Traffic Data
(s) when the data flow containing the request current urban traffic data is received, collect the requested data from the Store of Urban Traffic Data and send it to the Predict Short & Long Term Urban Traffic function in the data flow containing requested current urban traffic data
(t) as a result of (s) continuously monitor for receipt of the short & medium predicted urban traffic data flow
(u) when the data flow in (t) is received, load its contents int he store of Urban Traffic Data.

Diagrams

The Diagram(s) is (are) the diagram(s) where you can find the function :
  • DFD 3.1.1 Provide Urban Traffic Management
  • Functional tree 3.1

    • Parent Higher Level Function

    Input logical dataflows

    Output logical dataflows

    User needs

    Number

    Description

    2.1.1.1
    The system shall be able to produce information for travellers on the traffic and travel conditions of all relevant transport modes.
    2.1.1.3
    The system shall be able to collect traffic data for road network use analysis and prediction calculations.
    2.1.2.3
    The system shall be able to assist in the planning of (inter-modal) routes.
    2.1.4.1
    The system shall collect and report data as required by legally appointed authorities.
    2.1.4.2
    The system shall be able to archive (a summary of) historical data on transport demand and transport supply for all transport modes.
    2.2.0.2
    The system shall be able to recommend short term road maintenance activities, including winter maintenance, based on data collected from the road infrastructure possibly combined with the current and/or forecast weather conditions.
    6.1.1.4
    The system shall be able to provide extensive multi-modal trip information, e.g. prices, fares, routes, forecast & current traffic situations, traffic control, demand mgt measures, local warnings, special events, weather conditions, hotels etc.
    6.1.2.6
    The system shall be able to provide road and traffic information adapted to different classes of users, e.g. travellers, radio broadcasters, service operators.
    6.2.2.9
    The system shall be able to adapt the information to different classes of users, e.g. travellers, radio broadcasters, service operators.
    7.1.0.12
    The system shall be able to use different methodologies to control separate areas of the road network.
    7.1.0.6
    The system shall be able to help co-ordinate the activities of TICs and TCCs.
    7.1.0.7
    The system shall be able to exchange information between TICs and TCCs, including across national boundaries.
    7.1.0.8
    The system shall enable the data that it stores to be extracted by an operator onto a variety of media and used for other purposes, or by other organisations.
    7.1.0.9
    The system shall ensure that traveller information service providers are aware of the traffic management strategy, so that they can provide information that conforms to it.
    7.1.11.4
    The system shall be able to collect and store data from all car parks to provide a historical record.
    7.1.2.1
    The system shall be able to use consistent historical data to complement real-time data, when necessary.
    7.1.2.3
    The system shall be able to use historical data to complement predicted data, when necessary.
    7.1.2.7
    The system shall be able to provide historical and predicted data.
    7.1.5.7
    The system shall be able to recommend re-routing strategies to reduce congestion.
    7.1.8.1
    The system shall be able to transmit information to a vehicle to update its on-board database.
    7.4.1.11
    (X)FCD - The system shall enable a road-side device to send fused traffic data to the TCC.
    7.4.1.14
    (X)FCD - The system shall be able to send fused FCD to the TCC from a road-side device.
    7.4.1.15
    (X)FCD - The system shall be able to send XFCD to the TCC from the host vehicle.
    7.4.1.16
    (X)FCD - The system shall be able to add traffic data from the infrastructure (e.g. induction loops, radar) to the fused XFCD data of the road-side device.
    7.5.1.7
    The system shall enable the TCC to obtain travel times from cellular telephone service providers.
    7.6.2.14
    The system shall be able to send O-D data, from the navigation system, and current location data from the host vehicle to the TCC to enable geo-referenced travel times to be produced.
    7.6.4.1
    The system shall be able to exchange relevant information between adjacent TCCs and TICs to ensure the continuity of services for travellers.