The value of Object Type Library (OTL)

Knowing how, when, and what decisions were taken and who has responsibility for them, is of crucial importance to any infrastructure project.

An OTL, Object Type Library, is the unambiguous description of built environment concepts – both physical and spatial - from which this information is derived.

The contents of an OTL apply to the entire lifecycle of a project and include all sub-sectors in construction and groundwork, both residential and non-residential building, as well as the spatial (geo) environment.

Definition OTL:

Defining OTL, the INTERLINK report Information Management for European Road Infrastructure using Linked Data | Investigating the Requirements’ (final issue: March 31, 2017) states:

‘An object type library (OTL) is a library with standardised object-types names (e.g. road, viaduct) and properties or specifications. An object is described with its object-type data, geometry data and metadata, Metadata are data (or information) about the data of objects. Metadata are needed because each object type has its own properties. How the object types are grouped is called an ontology. The OTL can be linked to a data dictionary, with the definitions of object-types.’

Within an OTL, assets are described with the standardised language, syntax and semantics required for a reliable information exchange.

Example of an OTL:

Using the Millau Viaduct cable-stayed bridge in France as an example of an object type. An instance of this object type would be a data object carrying the relevant data about this bridge (see image).

The relevant object type data for such a bridge would depend on who is looking for the information:

  • For a designer, it could be the number of pylons, the number of spans, the spans lengths and the deck material.
  • A contractor may find a web link to a construction specification.
  • For an asset manager, the relevant data could be the expected residual life of the structure and the time to the next inspection of the bearings.
  • For the bridge inspector, it could be the access route for inspecting the pylons.

Objects can carry or reference graphical data, non-graphical data and metadata. An example of metadata for the Millau Viaduct object could be when and by whom the object data was last revised.

The OTL defines the data structure and the variables to be populated at different stages of an asset's life, often in the context of associated open data standards.


Examples of OTL are:

  • CB-NL, Concepten Bibliotheek (Concept Library), BIR Bouw Informatie Raad (Building Information Council, The Netherlands.
  • OTL-Rijkswaterstaat, The Netherlands, can be found at:
  • OKSTRA, ObjektKatalog für das STRaßen- und Verkehrswesen, Germany.


INSPIRE Conference 2018, Antwerp, Belgium

Sept. 18, 2018 - Sept. 21, 2018

The 2018 edition of the INSPIRE conference will take place in Antwerp, Belgium, 18-21 September. The motto of this years’ event is INSPIRE users: Make it work together!  

The European INSPIRE Directive leads to a digital highway for sharing information on Europe’s environment. Member states are rapidly extending this network to reach all levels of government and application areas beyond the environment. Now that we have this essential European facility in place, we can exploit it to the full to support the digital transformation of European society. 

The call for submissions is organised in 3 strands

INSPIRE the Users: In this strand special attention goes to inspiring the usage and users of INSPIRE. Both public and private parties are invited to share their experiences with creating applications that benefit from INSPIRE.

Doing it Together: This strand is dedicated to 'cooperation'. We are looking for examples where the cooperation between public and/or private sector organisations and programmes has been successfully developed to support the implementation of INSPIRE.

Making it work: The strand adressess a more technical approach to ‘make it work’. We are calling for submissions where implementation issues have been identified and where the source of the problems has been - or needs to be - addressed (e.g. Simplifications encoding, Automatisations, quality assessment, etc.).

7. OKSTRA®-Symposium in Bergisch Gladbach/Germany

May 15, 2018 - May 16, 2018

Schwerpunkte des Symposiums:

  • OKSTRA in der Anwendung, Austausch von Planungs- und Netzdaten
  • OKSTRA bezogene Forschungsergebnisse
  • OPEN Data und INSPIRE
  • Qualitätssicherung
  • BIM international und national
  • BIM-Pilotprojekte in Deutschland

 Zielgruppe des Symposiums:

Das Symposium richtet sich an Beschäftigte von Straßenbauverwaltungen aus Bund, Ländern und

Gemeinden, aus Planungsbüros, aus der Bauindustrie, aus Universitäten und Softwarehäusern.

Angesprochen sind alle, die sich über Nutzen und Stand des erfolgreichen Standards im Straßen- und

Verkehrswesen informieren möchten.

Presenting results from our Interlink testcase

OKSTRA, IFC und BIM: Neue Wege zum Umgang mit Straßeninfrastrukturdaten

Authors: Matthias Weise (AEC3), Ingo Schmidt, Jan Tulke (P+B4.0), Jochen Hettwer, Arnold Vogelsang (Interactive Instruments).