Low Level Function
3.1.1.5.10 Provide Urban Traffic Operator Interface

Overview

This Function shall be capable of providing the following facilities:

(1) The ability for the Road Network Operator to manage the control of traffic in the urban road network by changing the current urban traffic control strategy, except when it is imposed as part of an incident or demand management strategy, or to provide selective vehicle priority.
(2) The ability of the Road Network Operator to examine and update the sequence of urban traffic control strategies that are implemented automatically, to see the "log" of previously implemented urban traffic control strategy changes and to provide data that will be used to update the store of Urban Road Static Data through the Manage Urban Static Traffic Data Function.
(3) The provision of information to the Road Network Operator about the success or failure of any requested changes.
(4) The ability of the Road Network Operator to request and be provided with the current contents of the store of Urban Road Static Data through the Manage Urban Static Traffic Data Function.

Functional Requirements

(a) continuously monitor for the receipt of the input data flows from the Operator
(b) when the urban traffic commands data flow is received check that it is a valid instruction from the Operator and that all the parameters required by the command are present, otherwise get the Operator to provide them
(c) if the data flow in (b) contains updates to the urban traffic management strategies that are implemented automatically, or a request for output of the current strategies then send them to the Provide Planned Urban Traffic Management function using the planned urban data update data flow
(d) as a result of (c) wait for the planned urban data output data read data flow to arrive and when it does, output its contents to the Operator in the urban traffic responses data flow
(e) if the data flow in (b) contains an actual command to change the way that the traffic using the urban road network is being managed, send it to the Implement Urban Traffic Commands function in the operator urban management request data flow
(f) as a result of (e) wait for the operator urban management response data flow to be received and when it is, output its contents to the Operator in the urban traffic responses data flow
(g) if the data flow received in (a) contains the urban static network data or a request for its output, send it to the Manage Urban Road Static Data function in the urban static data changes data flow
(h) as a result of (g) wait for the operator urban road static data response data flow to be received and when it is, output its contents to the Operator in the data flow containing urban static road data
(i) if the data flow in (b) contains a speed setting send it to the Manage Urban Traffic Speeds function in the operator urban speed override data flow
(j) if the data flow in (b) contains an override to the current use of lanes in a segment of the urban road network, send it to the Manage Urban Road Network Lanes function in the urban operator lane override data flow.

Diagrams

The Diagram(s) is (are) the diagram(s) where you can find the function :
  • DFD 3.1.1.5 Provide Urban Traffic Management Faciliti
  • Functional tree 3.1
  • Parent Higher Level Function

    Input logical dataflows

    Output logical dataflows

    User needs

    Number

    Description

    7.1.0.10
    The system shall be able to manage traffic in all or part of the road network using a methodology that is appropriate for urban roads, e.g. using traffic lights at junctions and with the possibility of incorporating facilities for pedestrians to cross the road in a controlled manner.
    7.1.3.1
    The system shall enable a TCC operator to control, possibly remotely, infrastructure elements (e.g. traffic lights, VMS).
    7.1.3.2
    The system shall enable a TCC operator to log all significant incidents and to record free text messages prior to their output to travellers.
    7.1.3.3
    The system shall be able to provide a graphical representation of the road network (including equipment, incidents, traffic condition etc....) to TCC operators.
    7.1.3.5
    The system shall enable TCC operators to make temporary changes to the normal control strategy in real-time.
    7.1.3.8
    The system shall provide TCC/TIC operators with controlled access to all relevant systems.
    7.5.2.3
    The system shall enable a traffic signal controller to receive a request for a green phase from an approaching vehicle; in the event that more than one conflicting request is received at the same time they shall be prioritised (e.g. emergency vehicles before private vehicles), possibly by the TCC operator.