Application to functional module ’closed lane’

It is most illustrative to start the description of a sample module from the Modular Con-struction System with a functional module and broaden the obtained findings into a ge-neric description for the other viewpoints.

The selected module is implemented in the System Architecture described in chapter 8:

Determine the lane closed by the road works safety trailer. The module is part of the Road Works Warning service implemented in the C-ITS corridor, it receives as input informa-tion about a road works safety trailer, which is part of a short-term road works, e.g. its position. Output of the module is the exact lane on which the road works safety trailer is placed. This information might be used by subsequent modules to combine trailers that belong to the same short-term road works or to generate a precise warning. (Details on the whole process chain for the Road Works Warning service are available in section 8.7.) The functional module is linked to organizational modules, e.g. a road operator respon-sible for service provision. From a technical perspective links to central infrastructure components are likely.

5.5.1.1. Horizontal interfaces of ’closed lane’ module

For the description of the horizontal interfaces the concatenation of modules from the same viewpoint, here the functional viewpoint, are analysed. Therefore, the different processes and work flows that traverse the module are examined. The more complete the inspection of possible processes incorporating the module, the better the list of resulting interfaces.

Applying this to the module ’closed lane’ results in two types of horizontal interfaces:

interfaces to modules from the same level of detail which directly precede or follow the

’closed lane’ module and interfaces to modules that are rather sub-functionalities of the

’closed lane’ module. Both are depicted in Figure 5.3.

In the present scenario (Figure 5.3) the ’closed lane’ module (here shortened to: M2) is part of the Road Works Warning use case. As mentioned in the introduction it implements at least two interfaces (I₁and I₂) to its predecessor and successor modules. The predecessor module in the Road Works Warning use case (here shortened to: M₁) realizes the filtering of messages received from the road works safety trailer. The successor module (here shor-tened to: M₃) implements the combination of multiple trailers, in case that more than one road works safety trailer secures the short-term road works setup.

The ’closed lane’ module requires a submodule (here shortened to: M₂₁) that does the map-matching, a core feature of the ’closed lane’ module. The map matching done by the submodule might be realized with different algorithms. Each algorithm has advantages for specific use cases. Depending on the use case a suitable map matching module needs to be selected. Accordingly, different variations of the submodules are possible. Apart from that, the map matching submodule might integrate different maps, depending on the pref-erences of the actors responsible for the use case as a whole (here: short-term Road Works Warning). Usually, the submodule integrates the map already in use by the responsible actor. This ensures that the road works content is recorded based on the same geographic reference as other traffic relevant events.

The interfaces I₁, I₂, I₃ and I₄ can be implemented both as proprietary and generic in-terfaces, in the Road Works Warning use case proprietary interfaces will be used as the

Figure 5.3.: ’Closed lane’ module and its interfaces to neighbour modules and submodules module is tightly embedded between its neighbor modules. Though, the content passed over I₁and I₄will follow the data model developed for Road Works Warning in the C-ITS Corridor (section 8.7.4). Both interfaces transmit road works objects derived from this data model.

Summarizing this, the ’closed lane’ module realizes the following functionalities and in-terfaces:

• interface I₁: receive input data from ’filter messages’ module (M₁) – in this use case the interface is internal and proprietary

– a road works object is transmitted (based on the RWW data model defined in the C-ITS Corridor, Figure 8.12)

• module M₂: ’closed lane’ module extracts the position information from the received object and passes it to the map matching submodule (M₂₁) viainterface I2requesting to map the road works safety trailer (object) to a road element of the respective map

• module M21: map matching submodule runs its map matching algorithm on the road works safety trailer position and returns viainterface I₃the road element on which the trailer is parked / stopped / driving

• module M₂: for the exact determination of the roadworks layout the ’closed lane’

module combines the sign board configuration on the back of the trailer with the

re-sults from map matching (position of trailer), the ’closed lane’ module (M2) updates the road works object with the lane information

• interface I4: the ’closed lane’ module (M₂) passes the updated object to the module that combines multiple road works safety trailers (M3)

The corresponding interdependencies within the functional viewpoint are

• M1−→M2via I1: filter messages module→interface I1→’closed lane’ module

• M₂−→M₂₁via I₂: ’closed lane’ module→interface I₂→map matching submodule

• M₂←−M₂₁via I₃: ’closed lane’ module←interface I₃←map matching submodule

• M2 −→ M3 via I4: ’closed lane’ module → interface I4 → combine multiple road works safety trailers module

5.5.1.2. Vertical interfaces of ’closed lane’ module

The (horizontal) interfaces between elements of the functional viewpoint and the module

’closed lane’ are listed in the previous subsection. Aside from that there are as well (ver-tical) interfaces to the other viewpoints, organizational and technical, which are analyzed in detail in this section.

The links to other viewpoints which are as well part of the Modular Construction System are depending on the functional configuration. The combination, both with organizational and technical modules, is depending on the selection of neighbor modules and submodu-les tied to the functional module. The variety of generic interfaces for in- and output per se enables more options for the choice of organizational and technical modules, it poten-tially suspends the dependency introduced by the choices of preceding and consecutive functional modules.

The organizational aspectsaddress the responsibilities around the module ’closed lane’.

In general, the respective actors from the C-ITS Corridor will belong to the high-level role

’Functional Operation’ (section 7.1.3.2). From its subrole ’Generic functional operation’ the sub(sub)roles ’Content Provision’ and ’Service Provision’ come into consideration. Those might be combined with sub(sub)roles ’Road Operator’, ’Roadworks Operator’ and ’Infra-structure Operator’ from the subrole ’Specific functional operation’ (see as well Figure 7.2).

Examples in terms of respective actors are road operators like Hessen Mobil (Germany, fe-deral state Hesse), Strassen.NRW (Germany, fefe-deral state NRW) or ASFINAG (Austria).

Alternatively, the named actors might authorize other entities to take over this task. De-pending on the national legal and organizational background, other example actors might be service providers in the field of traffic management.

Thetechnical optionsinvolve different hardware solutions for the implementation of the

’closed lane’ module. Due to its dependency on a map, the module probably will be run-ning in a rather central infrastructure component, as the use of a map usually is closely related to licence fees which arise per instance in operation. Accordingly, candidate techni-cal components are located in the traffic control or cooperative centres. Possibly, roadside units come into considerations as infrastructure components.

Often, the selection of organizational and technical for the vertical interfaces cannot be

Closed lane module ID 0815-2016 The module determines the lanes closed in a road works by a road works safety trailer. Therefore, it receives information about the road works safety trailer, e.g.

its position. Output of the module is the exact lane blocked by the road works.

Addressed viewpoint organizational Xfunctional technical Cross-sectional aspects IT-security privacy quality N/A

Implemented in Reference Architecture(s)

C-ITS Corridor Germany

Horizontal interfaces

M₁−→M₂via I₁: filter messages module→interface I₁→’closed lane’ module

M2−→M3via I4: ’closed lane’ module→interface I4

→ combine multiple road works safety trailers mod-ule

M₂←−M₂₁via I₃: ’closed lane’ module←interface I₃

←map matching submodule

M₂−→M₂₁via I₂: ’closed lane’ module→interface I₂

→map matching submodule Vertical interfaces

organizational viewpoint

road operator service provider

technical viewpoint traffic control centre, cooperative centre

Table 5.2.: Description of ’closed lane’ module based on template for Modular Con-struction System 5.1

done completely stand-alone. Organizational and technical modules are often linked – actors usually do not support all possible hardware but only a specific selection.

5.5.1.3. Resulting template filling for ’closed lane’ module

The details collected and described in the previous subsections are finally summarized in Table 5.2.