Low Level Function
3.1.2.14.4 Output Inter-urban Traffic Commands & Messages

Overview

This Function shall be capable of providing the following facilities:

(1) The ability to send for output the contents of traffic management strategies so that the most efficient use is made of the inter-urban road network.
(2) The ability for the management strategies to include the output of messages to Drivers that will enable the use of road carriageway lanes, vehicle speeds and vehicle headways to be managed.
(3) The ability for these strategies to be overridden by the Road Network Operator through the functionality providing their interface, as well as by requests for access or use of particular lanes as part of a green wave route request for Emergency Vehicles.
(4) The ability to use current, historic and predicted traffic data from the inter-urban network and to change in real-time the actual traffic management commands being sent for output to take account of variations in this data.
(5) The ability to continuously adapt the management of the inter-urban road network to suit the actual detected traffic conditions.
(6) The ability to provide details of the current and previous modes of control on some or all parts of the inter-urban road network to the Road Network Operator through the functionality that provides their interface.
(7) The ability to monitor the results of the output of commands, so that alternative action can be taken if they are not followed.

Functional Requirements

(a) continuously monitor for receipt of either of the inter-urban command monitoring or override data flows from the Provide Inter-urban Road Operator Cmd Interface function, or either of the "strategy details" data flows, or the inter-urban incident strategy, emergency route, or coned area strategy request data flow, or the current inter-urban traffic conditions data flow
(b) when the selected inter-urban strategy details data flow is received in (a), check its contents and implement them by sending the inter-urban traffic management l&s reqyest and/ore inter-urban speed value and/or inter-urban traffic management c&i reqyest data flows to the Ouput Lane & Speed Messages to Inter-urban Roads or Detect Violartions on Urban Roads, or Ouput Messages & Commands to Inter-urban Roads functions
(c) as a result of (b) continuously monitor for receipt of the inter-urban traffic management l&s response and/or inter-urban traffic management c&i response data flows
(d) when either of the data flows in (c) is received check its contents and if the ouput in (b) is not being performed correctly, send the details to the Manage Inter-urban Traffic Commands & Messages function in the inter-urban strategy command response failure data flow, plus also send details of the failure in the inter-urban strategy command output failure data flow to the Evaluate Need for Equipment Maintenance function
(e) when any of the nter-urban incident strategy, emergency route, or coned area strategy request data flows is received in (a), check its contents and use them to override the outputs produced in (b)
(f) as a result of (e) repeat (c) and (d)
(g) wheb the current inter-urban traffic conditions data flow is received in (a) use its contents to modify any of the outputs being generated in (b) only
(h) when the inter-urban command monitoring data flow is received in (a), check its contents and if they are a request for monitoring to start commence providing the contents of the output data flows in (b) to the Provide Inter-urban Road Operator Cmd Interface function in the data flow containing inter-urban command monitoring data
(i) if the contents of the data flow in (h) were a request to stop a previously requested monitoring, then cease the activity in (h)
(j) when the inter-urban command overridedata flow is received in (a), check its contents and if they are a request for an override, implement it unless any of the data flows in (e) area being actioned, in which case ignore the request
(k) send the results of the action in (j) to the Provide Inter-urban Road Operator Cmd Interface function in the data flow containing inter-urban command override response

Diagrams

The Diagram(s) is (are) the diagram(s) where you can find the function :
  • DFD 3.1.2.14 Implement Inter-urban Management Traffic Strategy
  • Functional tree 3.1

    • Parent Higher Level Function

    Input logical dataflows

    Output logical dataflows

    User needs

    Number

    Description

    2.1.3.1
    The system shall be able to measure the effect of a strategy, and to modify it when necessary.
    5.2.0.2
    The system shall inform the TCC about the route that is intended for each green wave before it is used.
    7.1.0.11
    The system shall be able to manage traffic in all or part of the road network using a methodology that is appropriate for motorways, e.g. no junctions and pedestrian facilities, but with lane use management.
    7.1.0.12
    The system shall be able to use different methodologies to control separate areas of the road network.
    7.1.0.2
    The system shall be able to implement identified control strategies that conform with specified policy.
    7.1.0.4
    The system shall manage road traffic in such a way that levels of environmental (i.e. atmospheric and noise) pollution may be reduced.
    7.1.0.5
    The system shall manage road traffic in such a way that congestion (travel time) may be reduced.
    7.1.4.1
    The system shall be able to control the entries and exits to motorways.
    7.1.4.2
    The system shall be able to provide ramp metering (e.g. using traffic signals or barriers) at selected locations (e.g. slip road entrances to high speed roads).
    7.1.4.5
    The system shall be able to provide priority to selected travellers (e.g. PT, emergency vehicles, cycles, pedestrians) through the road network, including on motorways (when applicable).
    7.1.4.8
    The system shall be able to provide co-ordinated traffic management operations during periods of mass movement across (many) regions.
    7.1.4.9
    The system shall be able to provide specific traffic management for exceptional vehicles (e.g. very dangerous cargo, wide loads, etc.).
    7.1.5.1
    The system shall be able to provide control measures to protect road maintenance work and workers.
    7.1.5.5
    The system shall be able to close roads and advise drivers of a suitable diversionary route for a period of time.
    7.1.5.6
    The system shall be able to command drivers of certain classes of vehicle (e.g. heavy vehicles or tourist traffic) to take an alternative route for a period of time.
    7.1.5.8
    The system shall request confirmation of all exceptional measures before they are executed.
    7.4.3.7
    The system shall be able to advise a driver, via an in-vehicle device, which lane to use when passing an incident/accident.
    7.4.3.8
    The system shall be able to advise a driver, via an in-vehicle device, where to stop safely (e.g. an appropriate exit lane, hard shoulder).
    7.4.6.18
    The system shall be able to use a road-side device to warn drivers of any collisions that could occur with other vehicles and/or VRU that are approaching an urban intersection.
    7.4.8.7
    The system shall be able to advise the driver, via an in-vehicle device, of an appropriate lane to use to create a “blue corridor”.
    7.4.8.8
    The system shall enable the host emergency vehicle to “place” virtual cones around the site of an accident.
    7.4.8.9
    The system shall enable the driver of the host vehicle to be advised, via an in-vehicle device, not to enter a zone defined by virtual cones.
    7.5.1.10
    The system shall enable the service provided to the traveller to be passed from one TCC to another as the traveller moves from one area of coverage to another.
    7.5.1.4
    The system shall be able to monitor the current inter-urban traffic and weather/environmental conditions for the road network and recommend and/or set an appropriate traffic management strategy.
    7.5.1.5
    The system shall be able to manage the traffic in an area using a number of local semi-autonomous traffic management units, whose rules can be modified when required.