Traffic Management Systems - Status, Fault and Quality

 

Introduction

Traffic management in urban environment differs significantly from traffic management on highways. The major reason for this is the multiplicity of traffic participants and transport carriers, including pedestrians, bicycles, motorised private and commercial vehicles, public transportation by means of buses, trams, trains (metro), that either share transport paths, or of which the transport paths partly overlap. In addition to this complexity, self-driving vehicles, once introduced, will add further challenges for traffic management, including the need for electronic management of regulations and policies.

Regardless of how traffic management is being implemented, it is essential that reliable information on the status of the traffic and its traffic management tools, including various levels of potential faults, is available within due time by means of appropriate detection and reporting facilities in order to perform necessary counter-measures. The quality of traffic management is primarily determined by the design of traffic management systems, making use of trustable information on the actual status and potential faults of the traffic management system.

Monitoring and reporting of statuses and faults of a traffic management system requires appropriate communication means between the various entities of the traffic system, e.g. control centres and field devices. Considering the various traffic participants in an urban environment, a harmonized approach towards status, fault and quality in traffic management is necessary, and will become a pre-requisite once self-driving vehicles are introduced in a large scale. In future, high quality urban traffic management systems will not just be composed of control centres and field devices, but also of components installed in or carried by traffic participants. This leads directly to the need of standardized data and messages, and the concept of ITS stations introduced in ISO 21217. Such ITS station units, performing the exchange of data (including status and fault information) between each other, may become part of or even constitute the components of traffic management systems.

It is to be noted that ITS technologies developed in ISO TC204 and CEN TC278 under the acronym of C-ITS (Cooperative ITS) are applicable in the urban environment; i.e. U-ITS is not a new silo beside a C-ITS silo.

 

Objective

The objective of the project is expressed by the Prestudy Urban ITS and it is twofold:

  • to identify quality and performance criteria, i.e. service level agreements in terms of ITS performance e.g. availability, timeliness of data transactions or key performance indicators in terms of safety, efficiency and environmental impact, for the validation and assessment of traffic management services from suppliers, and
  • specify system status and fault information (particularly for the sub-systems in the field level), in order to support system monitoring and (semi-automated) fault clearance.

Further on, this project aims on contributing to the METR project of CEN TC278/WG17. METR is about "Management of electronic traffic rules".

 

Scope

The objectives result in a CEN Technical Specification

Intelligent transport systems — Traffic management systems — Status, fault and quality requirements

With the scope: Specify quality and performance criteria, and approaches to their evaluation, for the operation of traffic management systems, including factors affecting the effective integration of field and centre systems and services. To support this, specify a data model for system status and faults of components of traffic management systems. Present as informative annex a series of example use cases for the use of the quality and performance criteria, including design, procurement, and performance management.

Note that this scope excludes criteria and modelling of the status of the traffic itself, except insofar as this is related to the traffic management system performance.