4.1 TMS-Introduction


4.1.1 Overview

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:

  • TMS-01 Dynamic Lane Management
  • TMS-02 Variable Speed Limits
  • 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
Figure 29:  Overview over all Traffic Management services and the relation to the TMS introduction

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  

4.1.2 Purpose and aim of Traffic Management services Introduction

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.

Figure 30: “Traffic Management” as control loop

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.

  • Control services (TMS-01 to TMS-05), which purpose is to respond to events that can be precisely localised and which can be operated by a road operator alone,
  • Management services (TMS-06 and TMS-07), which are aiming at eliminating or mitigating problems of the incidents that effect greater part of the controlled network and that require the cooperation of more than one road operator.

4.1.3 Vision, Missions and Benefit of Traffic Management Core services What is the Vision?

Traffic Management Services are primarily aimed at three goals (separately or in combination)

  • Increasing traffic safety to prevent accidents
  • Improving the performance or optimising the use of existing network capacities
  • Mitigating the negative environmental effects of traffic What are the Missions?

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)

  • optimizing the capacity of existing roads by using dynamic devices that affect vehicle flow by assigning the number of lanes that are open or the types of vehicles which are authorized,
  • achieving a temporary clearance of lanes in case of accidents, incidents, road maintenance work or road construction measures (safeguarding of lanes),
  • allocating lanes on black spot areas (bridges or tunnels) or at locations with poor safety records.

TMS-02 Variable Speed Limits (Speed Control)

  • harmonising traffic flow,
  • increasing traffic safety by alerting and slowing down traffic approaching road works and incidents locations, 
  • adapting drivers speed dependent on road and weather conditions like rain, slippery roads or constricted visibility,
  • mitigating the negative environmental effects of traffic,
  • helping to protect vulnerable road users. 

TMS-03 Ramp Metering

  • preventing or delaying the onset of flow breakdown on the main carriageway, maximising throughput, without disrupting the urban road network.

TMS-04 Hard Shoulder Running

  • creating a dynamic extra lane triggered by traffic demand, at fixed times (peak hours) or even manually in case of bottlenecks/problem areas in the network with recurrent, but not constant, lack of capacity, i.e., recurrent peak hour congestion,
  • providing extra capacity for a dedicated set of road users (i.e. public transport vehicles).

TMS-05 HGV Overtaking Ban

  • reducing travel time and increasing safety for passenger vehicles by avoiding queues caused by slow lorries overtaking and unexpected lane changes,
  • reducing CO2 emissions,
  • ensuring a better coexistence of heavy goods vehicle drivers and the other road users.

TMS-06 Incident Warning and Management

  • creating the safest possible workplace at the scene of the incident to ensure the safety of Incident management responders and road users (upstream of the incident and on the other side of the road) to mitigate additional risks, i.e. secondary incidents.
  • diverting traffic via other routes to relieve the incident area and safeguard the mobility of traffic flow in order to reduce delays and increase reliability for the road user,
  • considering the consequences, including the economic cost incurred, of the damage to the vehicles and loads involved in incidents as well as the repair of possible damage to the road (surface, road equipment (e.g. guard rails) and civil engineering structures),
  • minimising the economic damage (vehicle loss hours) of incidents.

TMS-07 Traffic Management for Corridors and Networks

  • informing road-users in real-time and providing a consistent and timely service to the road user in case of unforeseeable events (incidents[1],, accidents) or predictable events (recurrent or nonrecurrent) providing seamless, language independent and consistent cross-border and traffic management and traveller information,
  • considering the network as a whole to optimise the use of existing road infrastructure capacities

More detailed information on the objectives of the Traffic Management Services can be found in chapters 4.2 to 4.8.  What is the contribution of TM Core services to overarching  European ITS objectives? Overview

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.

Figure 31: The Traffic Management service radars ITS service radars in detail

Dynamic Lane Management

Figure 32: Service radar “Dynamic Lane Management”
  • Safety
    • In most cases, Dynamic lane management (DLM) enables the temporary, demand-responsive capacity increase of sections (working sites and incidents are exceptions). Since a better distribution of traffic in the road section is possible by raising the number of lanes, the following behaviour can be better adjusted and the danger of accidents can be reduced. The impact analysis of comparable systems confirms the positive effect on traffic safety. Moreover, some DLM measures are clearly safety-oriented: lane allocation before and in tunnels, lane allocation due to incidents / accidents and lane clearing ahead of working sites. In literature, reductions in the number of accidents have been observed and range in most cases between 15% and 45%, with the reduction in some cases even exceeding 50%.
  • Environmental impact
    • Systems for dynamic lane management (DLM) have positive effects on the traffic flow and reduce traffic-related congestion and accidents (followed by further congestion). By means of traffic smoothing, noise and pollutant emissions are reduced. In literature, a reduction ranging from 3-10% for various pollutant emissions (CO2, NOx, CO, …) is reported.
  • Network efficiency
    • A demand-oriented increase of the capacity on route sections and at junctions clearly results in an improvement of the traffic flow in the whole network area concerned. Also, in case of incidents, the lane allocation helps keeping the traffic flow fluent by closing lanes and directing traffic to unblocked lanes. In particular, it has been proved that the number of accidents and their frequency decrease where the dynamic management of lanes is planned and activated properly. From the point of view of users, this also contributes to a more regular traffic flow (due to a better use of road capacity) and to a reduction of travel time losses.

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.

Figure 33: Service Radar “Variable Speed Limit”
  • Safety
    • The deployment of speed control offers an opportunity to improve traffic safety by using information for example about traffic flow, road and weather conditions, roadworks or unexpected incidents. Traffic volume-related and/or weather-related speed control reduces the risk of congestion and accidents. The impact analysis of existing implementations confirms the positive effect on traffic safety.
    • In the NEXT ITS literature research, an average reduction of 8% of both fatal and accidents with injuries is reported. Some additional highlights from the literature are provided below:
      • In a Danish study, accidents are found to be reduced by 50%, however in a short observation period of one year after implementation.
      • In Swedish studies summarized in the 2DECIDE toolkit, an evaluation of accidents considering a time period covering two years before and two year after implementation revealed a reduction of accidents by 20%. Another evaluation of a road weather controlled VSL implementation in Sweden, also summarized in the 2DECIDE toolkit, showed a reduction of fatal accidents by 40%.
      • In a Dutch study evaluating implementations in the Tilburg area, a limited positive effect has also been observed.
      • In an implementation in France, a reduction in the total number of accidents and victims of 25% with a strong decrease in the severity of accidents was observed.
      • In an URSA MAJOR 2 implementation in Switzerland, no impact on safety was observed. This was attributed to the fact that evaluations on safety require an adequately long time period for observations, which in that case was not available. However, another implementation in the MedTIS Corridor showed a slight decrease of accidents in the first year but an increase in the following two years.
  • Environmental impact
    • VSL systems on motorways positively affect the traffic flow and reduce traffic-related congestion and number of accidents (and the consequence of further congestion development). Improving the traffic conditions and having more uninterrupted traffic flow, also reduces noise and pollutant emissions.
    • VSL can also be used for environmental purposes only, with a reduced speed limit to mitigate noise and emissions when there is no congestion. This practice is also common in urban areas as well. In a Dutch study evaluating implementations in the Tilburg area, a reduction of NOx emissions of 18% was observed.
    • VSL system can also be used to increase the speed limit during low traffic demand periods to increase the level of service.  In these cases, the VSL system can also have negative environmental effects.
  • Network efficiency
    • Traffic demand-oriented speed control improves the traffic flow efficiency in the complete network area concerned. The duration of congestion is shorter, and the loss in vehicle operating and time costs is considerably reduced, as the capacity of existing road section is optimally used utilizing VSL. On motorways, traffic flow is more stable and has greater capacity after the VLS system is introduced.
    • Variable speed limits seem to be effective means for handling congestion and growing queues especially where the speeds tend to suddenly fall dramatically. The introduction of VSL in Mölndal and Tingstadstunneln has led to an increased average speed and 15 % shorter travel time on average (Results from the previously mentioned Swedish studies summarized in the 2DECIDE toolkit). Results from Denmark indicate a reduction of average travel times in the morning and afternoon peak periods ranging from 3-17%.

Ramp Metering

The main benefits of the service is achieved by:

  • Improved merging behaviour and less lane changing leads to a reduction in accidents
  • Increasing mainline traffic speed, reducing congestion and making travel times more reliable
  • Smoother traffic flows can lead to a reduction in emissions
Figure 34: Service Radar “Ramp Metering”
  • Safety
    • Improvement in the merging behaviour of traffic has a positive impact on traffic safety due to less lane changing. The breakup of merging slip road vehicle platoons reduces the incident and congestion potential on the main carriageway as well as the frequency of accidents. The long-term impact analysis of existing and comparable ramp metering systems confirms the positive effect on road safety due to the confirmed drop in the number of recorded accidents. Overall, crash reductions ranging from 5% to 40% are reported in literature. Rear-end and sideswipe crashes benefit the most from this service.
  • Environmental impact
    • It is believed that smoother traffic flow resulting in less speed variation on a metered motorway can lead to reduction in emissions and fuel savings. This is also the outcome of most evaluations in literature, while feedback from the experts during the external review phase also confirms the environmental benefits of the service. However, a few studies have found increased fuel consumption and emissions following ramp metering implementation. Some example evaluation results on the environmental impact of ramp metering are provided below:
      • Overall, the literature review of NEXT ITS reports results ranging from a reduction of 9% up to an increase of 4%.
      • In France, field tests of various control strategies measured a reduction of fuel consumption between 5-8%. Emissions were found to decrease respectively. Specifically, the HC and CO indices were reduced by 6-9%.
      • In the Netherlands, a study from Delft reports a measured reduction of emissions by 2%. However, other studies from the Netherlands even indicate an increase of emissions between 1-4%.
  • Network efficiency
    • Network efficiency impacts include the reduction of network travel time variability and increased throughput by eliminating the stop-go behaviour associated with congestion. Ramp metering significantly improves the traffic flow on the main carriageway therefore reducing travel times/ costs and operating costs. There are several studies related to the impact of ramp metering on traffic flows:
      • In Germany, traffic speed increases of up to 35% and up to 50% less congestion were experienced. 
      • The UK Highways England found that the overall increase in peak period traffic flows observed on the mainline after the installation of ramp metering varies by site with individual increases in traffic flow ranging from 1 – 8%. Despite the increases in traffic flow the implementation of ramp metering has resulted in downstream traffic speed increasing by between 3.5% and 35%. 
      • Highways England found an average journey time saving for mainline traffic of 13% across all sites evaluated. The average on-ramp delay per vehicle with ramp metering operational ranged from 15s to 78s, however the sites with the highest delay on the on-ramp in general also delivered the highest benefit on the main carriageway. 
      • In the Netherlands an increase of capacity of 0-5% has been measured, with an average of 2% speed on the main carriageway showed increases in the range of +4 km/hr to +30 km/hr.
      • The EURAMP Project impact analysis found ramp metering could improve Total Time Spent (TTS) in the system; this includes time on motorway, on ramps, travelling and waiting time.
      • In France, field tests of several control strategies were carried out with positive results compared to the “no control” scenario: Mean speed increased between 5-12% and time spent in the network decreased by 10-12%.  

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:

  • Increasing capacity on the network by opening an extra lane, and in most cases varying the maximum allowable speed which together has the effect of improving the efficiency along the section of road where the scheme is implemented.
  • Reducing number of lane changes, increasing headway and reducing speed which leads to a reduction in accidents.
  • Smoothing the flow of traffic which can lead to a reduction in emissions.
Figure 35: Service Radar “Hard Shoulder Running”
  • Safety
    • Hard Shoulder Running enables the temporary, demand-responsive capacity increase of road sections. This results in a better distribution of traffic by allowing road users to adjust more easily to dangerous situations and results in reduction of accidents due to the decrease/elimination of (upstream) congestion. The use of Hard Shoulder Running implies a decrease in the accident rate overall if the infrastructure has been significantly adapted for its use. In general, the impact analysis of comparable systems confirms the positive effect on traffic safety.
    • Note: However, Hard Shoulder Running may have negative impacts on safety, for example when broken-down vehicles need to stop. To avoid this, HSR sections have to be monitored and controlled and the operator’s response to such a situation has to be as fast as possible. In addition, due to the safety advantages of a closed hard shoulder, it is advised to use the service temporarily, when the need for extra capacity arises.
  • Environmental impact
    • By providing extra capacity, Hard Shoulder Running systems reduce congestion and journey times.
    • This improves the efficiency of journeys and reduces the pollution generated by each journey. Indicative results from literature show a potential reduction of 4-8% of pollutant emissions (CO2, NOx) and 6-10% of PM10.
    • If traffic flows do not increase, emissions are likely to be reduced. The increased capacity of the motorway could attract more users and lead to an increase of emissions locally. However, from the perspective of the corridor/network, if the motorway with Hard Shoulder Running attracts traffic from alternative routes, e.g. local roads, an increase in traffic flow on the motorway might not be negative for the environment.
  • Network efficiency
    • A demand-oriented increase of the capacity on route sections and at junctions results in an improved traffic flow on the whole network area concerned. From the point of view of users, this also contributes to a more regular traffic flow (due to a better use of road capacity) and to a reduction of travel time losses.
    • The impact analysis of comparable systems confirms the positive effect of Hard Shoulder Running on network efficiency. Results from implementations on the URSA MAJOR and Arc Atlantique Corridors show a reduction in travel time of at least 8%, capacity increases between 9-19% and reduction of congestion events by 24%.
    • Finally, it can be noted that compliance of the road user is another relevant aspect of network efficiency. Under-utilisation of the hard shoulder lane by the users decreases the effect of the measure.

HGV Overtaking Ban

Network efficiency and safety are assessed as the main benefits of the HGV Overtaking Ban service.

Figure 36: Service radar “HGV Overtaking ban”
  • Safety
    • The previous deployments of HGV overtaking bans have demonstrated safety improvement. This is particularly accurate on sections where the percentage of accidents due to a high level of lorry traffic is high.
    • One additional major impact of this measure concerns the psychological comfort brought to car drivers. Investigations in some countries show that dynamic overtaking bans for HGVs (concentrated on peak hours) provide considerably better results than static overtaking bans for HGVs.
  • Environmental impact
    • Improved network efficiency and network management help to reduce vehicles’ emissions. This is also observed in practice. For example, following the French experimentation of this service on ASF network during summer 2007 peak traffic periods a decrease of polluting emissions was recorded (-500 tons of CO2) due to the congestion drop (-7%).
    • Network efficiency
  • Network efficieny
    • An HGV overtaking ban positively impacts the network in terms of efficiency. The existing deployments and evaluations show:
      • A speed homogenisation on each lane,
      • An average speed increase on each lane in the case of light traffic (< 2000 veh/h for 2 lanes),
      • An increase of light vehicle speed in the case of heavy traffic (> 2000 veh/h for 2 lanes),
      • A decrease of traffic jams during peak traffic periods.

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

Figure 37: Service radar “Incident Warning and Management”
  • Safety
    • The application of measures for Incident Warning and Management offers the opportunity to optimize road safety where dangerous situations occur suddenly. Quick reaction on incidents contributes significantly to the prevention of secondary incidents. Based on data from MedTIS, secondary incidents consist 4-12% of the total number of incidents and a timelier reaction on incidents was found to reduce overall incident numbers from 1,6%. Therefore, this service contributes to a significant reduction of especially secondary incidents. Results from the NEXT ITS literature research report a similar overall reduction of accidents. 
  • Environmental impact
    • The service has a significant impact on polluting emissions, mainly through its high impact on network efficiency, reduction of congestion and secondary incidents. 
  • Network efficiency
    • Demand-oriented incident warning and management improves the flow of traffic on the network concerned. In this way sudden braking manoeuvres and/or rear-end collisions without braking can frequently be avoided. Furthermore, effective incident warning and management can reduce congestion in relation to accidents on the road by optimizing clearing processes, paying attention to leading traffic past or around the scene of the accident and giving drivers on the way towards the accident an opportunity to choose another route or even drive later in case of a motorway closing. This can significantly reduce the level of congestion, delay and cost due to these negative factors, including costs associated with asset restoration.
    • The NEXT-ITS literature research for this service has concluded to an average reduction of approximately 10% in vehicle congestion hours and 2% in vehicle hours driven achieved with efficient incident management. This identified significant impact on network efficiency is also in line with experiences submitted during the external review phase.

Traffic Management for Corridors and Networks

Figure 38: Service radar “Traffic Management for Corridors and Networks”
  • Safety
    • Timely and effective measures in case of major incidents serve to mitigate safety impacts. The quick and consistent provision of traveller information such as “Forecast and Real Time Event Information” (see 3.2) and “Incident Warning and Management” (see 4.7), as a part of the TMP measures, contribute to safety by warning travellers to reduce their speed.
  • Environmental impact
    • Reduction of environmental impacts due to re-routed vehicles can be estimated, if the additional length of the alternative route is appropriate to the congestion length. TMPs are also highly relevant in order to improve air quality in cities, e.g. by traffic information or traffic management measures.
  • Network efficiency
    • The main benefit in terms of network efficiency is the reduction in delays and travel time through the use of effective and timely control and information measures in the case of major incidents. Within TMPs not just the disrupted road section but the whole surrounding network (and sometimes even other transport modes) should be considered. This ensures a more efficient use of existing traffic infrastructure.

4.1.4 The Traffic Management Value Chain Functional architecture and interfaces

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: The Traffic Management value chain (basic model)

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.

  • On the left side of the figure the content segment with the so-called content detection (collection) and content processing is shown. Event messages (2) and real-time traffic data (3) are constantly monitored on relevant Traffic Management network segments and interpreted as traffic situations. If predefined threshold values are exceeded, this creates a predefined situation (4) identifiable in the planning database (1).
  • On the right side of the figure the service segment is shown. The action instruction linked to the identified situation is implemented in the form of one or a bundle of individual measures (5). On the one hand these consist of the switching of the available actuators of the road operator for traffic control and traffic guidance (variable messages sign or information display, traffic lights, P+R signs…) (6) and on the other hand the accompanying publication of relevant Traffic Management information on (mobile) Internet (applications) (7).

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.

Figure 40: The Traffic Management Value Chain (with NAP-model)

Driven in particular by the Delegated Regulations of the European Commission:

  • (EU) 886/2013 of 15 May 2013 on “the provision, where possible, of road safety-related minimum universal traffic information free of charge to users”, 
  • (EU) 2015/962 of 18 December 2014 on “the provision of EU-wide real-time traffic information services”,

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.

Figure 41: The Traffic Management Value Chain (with short-range C-ITS facilities – the  cellular C-ITS messages are transmitted as the Network based communication 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:

  • for the forward channel, various ISO and ETSI standards using “C-ROADS C-ROADS Message Profiles” and
  • for the return channel various ETSI standards using the CAR 2 CAR Communication Consortium Basic System Profile. TM service provision with new cooperation models

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[1] 

Cooperation models from SOCRATES 2.0[2]

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[3]:

  • Degree of commonality: To what extent is a common plan for coordinated action agreed, are all actors developing a common situation picture or a common view, or are the actors acting independently of each other?
  • Level of detail in the provision of information and strategy: What is the level of detail in the provision of information? A distinction must be made here:
    • Situational: data from sensors, detectors, etc. (status/situation of transport networks and traffic flow).
    • Operational: Transmission of information on concrete actions and measures of traffic management.
    • “Tactical” information: Information on the motives of public traffic management (“motivation”) to trigger certain strategies or actions at a given moment.
    • Strategy: Transport policy objectives, priorities and basic traffic management strategies. This also includes (political) targets (e.g. particulate matter alarm, CO2 reduction, routing compatible with the city, etc.), which traffic management must take into account.
  • Degree of commitment between the actors involved: Are the actors free to use or implement the information, plans or strategies, or have the actors agreed on the use, compliance and achievement of certain targets?

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):

Figure 42: SOCRATES Cooperation models

The three cooperation models (CM A to C) build on each other:

  • In the simplest model (CM A), traffic data and information are collected or measured individually by public and private actors and then made available to all actors. In line with the broad approach of SOCRATES2.0, the data provision includes both public sector data (e.g. data from detectors) and data from routing services. How the other actors then handle the data or how they use it is up to each individual.
  • CM B (common view) goes one step further, in which all actors agree on a common traffic situation picture on the basis of the jointly exchanged data. Nowadays, each actor (e.g. Traffic Control Centre A, Routing Service A, Routing Service B, MaaS Service C, regional association 1 …) creates its own traffic situation picture based on the data it collects. Since no actor has access to all data, the respective traffic situation pictures are “distorted” and do not reflect the entire traffic situation / mobility behaviour. By making all available data from all actors available, new opportunities would be created to generate a complete and ultimately common picture of the traffic situation in a region. The aim is to achieve a common understanding of the problems in the mobility sector.
  • The third and most profound cooperation model is that of coordinated actions (CM C). Based on common data and a common situation picture, actions of all actors are coordinated, whereby here an action can be understood as an individual strategy recommendation or measure (e.g. changing permissible maximum speeds on a route section) as well as the joint development of KPIs or transport policy objectives.

All three cooperation models require a different, strongly developed mediating role:

  • For the pure data exchange in CM A no intermediary is required.
  • In CM B the intermediary could take on the role of a (neutral) traffic observer.
  • In CM C the mediator additionally takes on the roles of strategy management, traffic manager and impact analysis.

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[1]:

  • Data cooperation
    • The aim of the data cooperation is to create an improved data basis for the assessment of the traffic situation for all players through mutual data exchange, thus contributing to an improvement in public strategies as well as individual route recommendations. This is based on the acknowledgement that currently no actor has a complete overview of the traffic situation because nobody has access to all available data. Only a mutual exchange of data enables a complete view.
    • The public authorities could obtain aggregated data from the routing services, in particular, based on FCD, while the routing services are particularly interested in public planning data and event data.
    • LENA4ITS proposes to organize the data exchange on the basis of bilateral agreements via National Access Point MDM.
  • Strategy Cooperation
    • In the strategy cooperation, the public authorities and routing services cooperate with each other with the aim of harmonising suitable strategic recommendations. In particular, the aim is to integrate public strategy recommendations into individual routing; in addition, a bidirectional exchange of recommendations in the direction of cooperative traffic management is also conceivable in the future.
    • Within the framework of this cooperation, the public authorities provide coordinated dynamic strategy routes, while the routing services include them in the individual routing according to certain specifications on the basis of concrete agreements. The implementation of the strategy exchange is also to be carried out via the National Access Point MDM.

As shown in Figure 43 LENA4ITS distinguishes the following levels of strategy cooperation:

Figure 43: LENA4ITS cooperation models
  • Level 1 – Conditional display: A public strategy route is made available to road users as an alternative route after positive evaluation by the routing service (in addition to the route recommendation of the routing service itself). If the evaluation is negative, the strategy route is not displayed. The road user can then choose which recommendation to follow. The evaluation by the Routing Service is based on three criteria:
    • Quality index: By a quality index provided by the public authorities,
    • Trust index: By means of a trust index determined by the routing service itself, which changes depending on the issuing authority (how reliable is the issuing authority?)
    • Case groups according to user settings.
  • Level 2 – Mandatory display: The public strategy route must always be displayed by the routing services as an option next to their own route recommendation. Here too, the road user decides which route to use. A corresponding attribute (e.g. “binding”) must be set in the strategy message so that the routing service knows that this strategy recommendation is mandatory to be displayed.
  • Level 3 – Sovereign order: Mandatory takeover of the public strategic route. Any route recommendations of the routing services are discarded. The road user cannot choose between different route recommendations.
  • Level 4 – Burden-sharing routing (future option): Here, the public authorities and the routing services cooperate in such a way that, based on the current traffic situation, the traffic flows are distributed as best as possible over various route alternatives, taking into account their individual destinations and free remaining capacities. The public authorities pass on a strategy route to the routing services in the form of a proportionately dosed route recommendation, whereby the latter take the proportions into account by (random) allocation.

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”.

[1] VON DER RUHREN, 2014, p. 39ff.

[1] http://tm20.org/final-reports-on-task-forces/

[2] https://socrates2.org/


[1] 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.