This introduction provides an overview of the structure of Traffic Management Services and describes from different points of view aspects, which are common for all services of the whole spectrum of Traffic Management services. This introduction has been prepared to avoid repetition in the specific descriptions of the Traffic Management services.
As shown in Figure 29, the set of TM services comprises seven different ITS Core services, in particular:
In the following section, the profile and other important aspects of Traffic Management services are discussed in more detail:
— Purpose and aim of Traffic Management services
— Vision, Missions and Benefit of Traffic Management Core services
— The Traffic Management value chain
Definition of “Traffic Management”
“Traffic Management” means the influencing of traffic through a bundle of measures in order to coordinate traffic demand to the existing traffic system supply to guarantee traffic safety at the highest possible level, to increase the efficiency of the network to the maximum possible and to reduce traffic-related environmental impacts as far as possible.
“Cross Competence Traffic Management” means that traffic situation is influenced by a bundle of measures in order to optimally coordinate the traffic demand and traffic systems supply beyond the borders of sovereign independently operating road operators optimally. These strategies include measures for the spatial, temporal or modal shift of traffic. In addition to the general objectives of traffic management, it is important to provide the road user with information beyond the limits of own responsibility.
Control loop “Traffic Management” as a principle
From a technical point of view, traffic management is based on the control loop principle, which is based in the theories of controlling technical processes A “control loop” serves to constantly counteract undesired setpoint deviations of a “controlled system” caused by external disturbance factors on the basis of previously defined operating rules and action guidelines.
On the one hand, the state of the “controlled system” is continuously monitored and measured and on the other hand, the “controller” influences the system in such a way that it operates in accordance with the specified policy and rules when deviations on the monitored subsystems are registered. If this principle is transferred to traffic management, “road network and the traffic flowing on it” can be seen as the “controlled system” and the “Traffic Manager” is the controller, which is supported by fully or semi-automatic, traffic-dependent decision-support or even fully automatic Intelligent Traffic Systems (ITS).
The traffic manager uses systems and technologies which are capable of influencing the behaviour of road users. This requires a range of field devices (detectors/sensors) to measure the actual traffic and weather circumstances in the controlled system, a software-based process (centralised or distributed) that may involve human actions, the transmission of information to road users by means of signals, traffic signs and barriers.
By their nature Traffic Management services can be divided into two categories.
Traffic Management Services are primarily aimed at three goals (separately or in combination)
The Traffic Management services have specific missions to ensure safe driving and utilize the available road capacity in a optimal way. The real-time management monitors traffic flow and driving conditions to identify expected or unexpected events or incidents to make needed control measures to fulfil its missions.
In summary and as an overview, each Traffic Management service pursue the following specific objectives.
TMS-01 Dynamic Lane Management (DLM)
TMS-02 Variable Speed Limits (Speed Control)
TMS-03 Ramp Metering
TMS-04 Hard Shoulder Running
TMS-05 HGV Overtaking Ban
TMS-06 Incident Warning and Management
TMS-07 Traffic Management for Corridors and Networks
More detailed information on the objectives of the Traffic Management Services can be found in chapters 4.2 to 4.8.
Figure 31 presents the Service Radar diagrams for the Traffic Management ITS core services of the handbook. As shown in the radar diagrams, the main benefits delivered by TM Core services relate to safety and efficiency. Their specific effects are discussed in more detail in the following section.
Note: As already mentioned in chapter 2.3, the Service Radars of the various services are not in relation to each other and not directly comparable.
Dynamic Lane Management
Variable Speed Limits
The common main objectives of VSL is both to support drivers in travelling at a safe speed and to have less interrupted traffic flow. In some cases, speed limits are also used to mitigate environmental effects, such as noise or pollution.
The service radar indicates the general expected impact of the implemented VSL systems. On a specific implementation, however the outcome may be very different from the general results, because the system are designed from the problem-oriented point of view. Essential things in implementing a VSL system are the main effects the system are designed for and what are the parameters that are used for the control of the system. The control parameters may be road and weather conditions for safety or traffic flow information for efficient use of road network.
The main benefits of the service is achieved by:
Detailed evaluation results from several sites and testing various algorithms can be found in the European Ramp Metering Project EURAMP Deliverable 6.3.
Hard Shoulder Running
The main benefits of the HSR service are achieved by:
HGV Overtaking Ban
Network efficiency and safety are assessed as the main benefits of the HGV Overtaking Ban service.
The service contributes to optimise the use of the network, especially on sections where the percentage of HGV traffic superior to 10%. This potentially concerns a substantial part of the TEN-T Road Network.
Incident Warning and Management
Traffic Management for Corridors and Networks
The TISA Value Chain Model
Traffic Management means value creation for road users. Planning data, traffic-relevant messages on traffic-related events and real-time traffic data are refined into information that creates added value for travellers. Gathered information can serve as a sound basis for decision-making processes in Traffic Management systems.
Figure 39 shows the approach of the basic value chain model for Traffic Management on the public road operator’s side, based on the “TISA Value Chain Model”. Traffic Management processes the gathered data and creates additional value of data using decision making mechanisms.
Extensions of the TISA Value Chain Model
Mainly driven by the European Directive 2010/40/EU, to find a response to the increase in the volume of road transport to the growth of the European economy and mobility requirements of citizens, that cause increasing congestion of road infrastructure and rising energy consumption, as well as environmental and social problems, the ITS value chain has been significantly extended by opening it up to private service providers and by applying new C-ITS technologies.
Extension of the TM Value Chain according to Delegated Regulations of the European Commission
Figure 40 shows the current form of the ITS value chain, which is based on the obligation of the European Delegated Regulations to provide digitally available traffic and travel information at the National Access Point.
Driven in particular by the Delegated Regulations of the European Commission:
and the associated requirement to introduce so-called National Access Points (NAPs) as well as to use DATEX II profiles for data exchange, the value chain of public road operators went through a significant expansion (see Figure 40).
Since the Delegated Regulations came into force, European road operators are obliged to publish digitally available information on the NAP. This is the first time that such data and information should be made publicly available outside the domain of public road operators and can be used by (private) mobility service providers, for example, but also by other road operators for their own purposes. With regard to traffic management, this information obligation applies to the information outcome of measures and actions to be taken as a result of a Traffic Management decision.
Appropriate DATEX II profiles for data exchange with the NAP are defined in the CEN/TS specification 16157- 8:2020.
As Traffic Management services usually use Variable Message Signs (VMS) installed at the roadside or overhead, thus, additionally and in parallel, the corresponding information can be published via the National Access Point for the use of private service providers or other road operators.
A possible extension of the NAP-functionality and an added value for the traffic management value chain is the so-called “return channel” (see patterned red arrows in figure 40). The aim of this extension is to provide public road operators with information about the driving or mobility behaviour of individual customers of the service providers, which they cannot obtain with their own means of real-time data and information detection.
Extension of the TM value chain according to C-ITS
The value chain for Traffic Management is further extended by new cooperative technologies
(C-ITS), as they are now being piloted and deployed in the European cooperation project C-ROADS. As already described in the generic interface implementation model (chapter 2.5.1), it adds two interfaces (2 and 3) on the short range (see Figure 41). The transmission of C-ITS messages via established cellular communication follows the network based communication path as illustrated in Figure 40.
The aim of this extension is to enable the road user to be reached directly without distraction. Through C-ITS warning services like Traffic Jam Ahead or Road Works Warning. Messages can be sent to the appropriate road user and help to avoid accidents. Information messages like speed recommendation can be sent to improve fluency of traffic flow and reduce travel times. On the other hand the infrastructure can be supported with additional single vehicle data to improve decisions and actions.
Different standards are used for the exchange of information via short-range communications:
The above described functional and technical extensions of the ITS value chain also open up completely new possibilities for cooperation between public road operators and public and private service providers in the sense of a Cooperative Traffic Management. This has led to a number of initiatives and projects dealing with the possibilities of the extended value chain with the aim of developing new cooperation and business models for collaboration between public road operators and private service providers.
TM2.0 – Traffic Management 2.0
Above all, the TM2.0 Innovation Platform initiative must be mentioned, which was launched in 2014 under the ERTICO umbrella of activities, bringing together 40 members from all ITS sectors to focus on new solutions for advanced interactive traffic management.
Since the foundation of TM 2.0, various task forces have worked out comprehensive concepts for various topics on how public road operators can cooperate with public service providers
Cooperation models from SOCRATES 2.0
SOCRATES2.0 is a pan-European project that brings together road authorities, service providers and car manufacturers with the intention to set new standards to share and integrate traffic information. This shall enable effective traffic management and shall open the door to innovative traffic information and navigation services.
SOCRATES2.0 has identified three key components of a future-oriented Traffic Management cooperation model:
The model is depicted in Table 25.
Table 25: SOCRATES2.0 Cooperation matrix
Based on the findings of the SOCRATES2.0 pilot studies, SOCRATES2.0 has developed three cooperation models (CM):
The three cooperation models (CM A to C) build on each other:
All three cooperation models require a different, strongly developed mediating role:
LENA4ITS cooperation models
LENA4ITS is an already completed German project in which a model for the cooperation of public traffic management and private navigation service providers was developed. The project distinguishes between data and strategy cooperation; the latter is further subdivided into four different levels:
As shown in Figure 43 LENA4ITS distinguishes the following levels of strategy cooperation:
Both types of cooperation can be considered independently, but according to LENA4ITS, a strategic cooperation will enjoy lower risk, better results and higher mutual trust if it is flanked by data cooperation.
Overall, the cooperation models presented increase with each level the commitment and intensity of the cooperation between public authorities and routing services. In the absence of overriding legal or normative guidelines, LENA4ITS concludes, “… this presupposes a well-founded interest on both sides and a corresponding drafting of bilateral cooperation agreements”.
 VON DER RUHREN, 2014, p. 39ff.
 KOLLER-MATSCHKE, 2018; YPERMAN, 2018
 Incident: situation on the road that is not expected or foreseen which may or may not lead to an accident (collision) but impacts on the safety and/or capacity of the road network for a limited time period.