OGC and buildingSMART International developing InfraGML, a new standard for land and infrastructure information

Contributed by: 
Paul Scarponcini

LandXML is a non-proprietary XML (eXtensible Mark-up Language) data file format containing civil engineering and survey measurement data commonly used in the Land Development and Transportation Industries.  The LandXML user community consists of over 650 organizations with 750 members in over 40 countries and the standard is supported by over 70 registered software products.  

The Open Geospatial Consortium (OGC) Land And Infrastructure Domain Working Group (LandInfraDWG) was chartered in 2013 to “focus on determining how best to integrate and support the LandXML schema within the OGC framework, as well as how to better manage and integrate CAD-based land information with other OGC standards.”  LandXML data is of value to the larger geospatial data community, but currently the format is not integrated with any of the OGC’s or ISO’s geospatial standards.  Both the land and infrastructure user domain and the geospatial technology user domain would benefit from integrated access to the two types of information.

One of the initial goals of the LandInfraDWG was to gain a better understanding of exactly what LandXML is and does.  LandXML-1.2 contains almost 5000 lines of minimally documented XML code covering some 16 subject areas.  There is no formally published documentation, user guide, requirements definition, or underlying conceptual model.

The Land and Infrastructure Standards Working Group (LandInfraSWG) was therefore chartered.  Its first task was to develop a UML as-is conceptual model of LandXML-1.2 to:

  1. Aid in the understanding of what LandXML 1.2 is and does

  2. Provide the basis for a conceptual model of what a future Land standard should do, based on an assessment of user requirements

  3. Establish a single set of consistent concepts that could be implemented in any set of potential implementation-specific standards, such as a LandXML 2.0, a LandGML, a LandSQL, etc.

This reverse engineering of LandXML revealed a number of problems with LandXML as well as broad disparity with the OGC standards baseline. These findings are summarized in the working groups’ November 5, 2013 “InfraGML Proposal (OGC Document 13-121r1)” plan of action.

The OGC LandInfraDWG accepted the proposed plan of action. The plan, in summary, calls for starting fresh and developing a new candidate standard – the OGC InfraGML Encoding Standard – that provides a use case driven subset of LandXML functionality, but that is implemented with the OGC Geography Markup Language (GML) and supported by a UML (Unified Modeling Language) conceptual model.  This new standard would:

  • be supported by a recognized, dependable Standards Developing Organization, OGC

  • align with existing OGC (and TC211 and SQL/MM) standards, including the OGC modular spec

  • benefit from functionality already supported by GML, including features, geometry, coordinate reference systems, linear referencing, and surface modeling (TIN)

  • initially focus on survey, alignments, and land parcels, the subject areas for which there are identified needs and committed resources for development

  • using modular extensions, be able to expand into other LandXML areas (e.g., pipe networks) as resources become available to develop these extensions

  • be use-case driven

  • be based on a UML conceptual model developed prior to the GML encoding (and any other future encodings)

  • have more up-to-date functionality

  • be synchronized with the concurrent efforts by buildingSMART in their development of Infrastructure-based Industry Foundation Classes (IFCs)

  • be more easily integrated with CityGML and TransXML


The OGC LandInfra SWG has begun this work, and very importantly, the work is being done jointly with buildingSMART International, the organization that is actively working on a set of Industry Foundation Classes (IFCs) for Building Information Model (BIM) interoperability. An OGC/buildingSmart International MOU was signed in March 2014, and progress on development has been good.  In coming months a draft conceptual model will be completed and published. Comments will be solicited from the existing LandXML community and others, including users as well as software developers. Comments will be addressed in revisions to the conceptual model before work begins on the GML implementation.