Combining OpenGIS and OpenStreetMaps

25 August 2008, 9:28am

Routing based on OGC standards and open geodata from Denmark to Italy with OpenRouteService.org.

The open route service for pedestrians and bicycles based on open standards and OpenStreetMap data is expanding in functionality and coverage

Free user generated content is one of the pillars of successful web2.0 applications. For example OpenStreetMap (OSM) is a project where a community of volunteers generates a free world map, which in some cities is already more detailed than commercial or government data. But up to now the worlds of those web2.0 collaborative projects / Volunteered Geography (Goodchild) and the world of GI standards used by the GI-economy and defined by the Open Geospatial Consortiums (OGC) were still somewhat separate. OpenRouteService.org is trying to bring these two worlds together. It is the first routing service that uses OSM data and provides those through the standardized interfaces specified by the Open Geospatial Consortium (OGC) within the OGC Open Location Services initiative (OpenLS).

OpenRouteService now supports routing from Denmark to Italy. Not only Germany, but also the countries Switzerland, Austria, Italy, Denmark and Liechtenstein are currently supported by the OpenLS Routing Service and also the OpenLS Directory Service (POI Search), the OGC WMS and WFS used by OpenRouteService.org. The version for UK GB will go live soon; the coverage will further be extended.

Routing services are probably the most important application for street data. While there are some applications that can provide such functionalities also in combination with OSM data, we focus here on an approach based on the concept of interoperable web services and open standards. But OpenRouteService is much more than only a routing service: it uses a wide range of OGC services based on OSM data that also could be used in other applications and scenarios.

Currently the following OGC services have been implemented within the frame of OpenRouteService.org based on OSM data:

- The OpenLS Directory Service is a service that provides access to an online directory (e.g., Yellow Pages) to find the location of a specific or nearest place, product or service.

- The OpenLS Location Utility Service provides a Geocoder/Reverse Geocoder; the Geocoder transforms a description of a location, such as a place name, street address or postal code, into a normalized description of the location with a Point geometry

- The OpenLS Presentation (Map Portrayal) Service portrays a map made up of a base map derived from any geospatial data and a set of Abstract Data Types as overlays.

- The OpenLS Route Service determines travel routes and navigation information according to diverse criteria. This has been realized for
• cars: fastest
• cars: shortest
• cars: for fastest and shortest additional option: no highway
• cars: use realtime traffic (TMC), for Northrhine-Westphalia and Bavaria
• bicycles
• pedestrian
• further extensions (particular options for different tyepes of bicycles etc.) are planned or in work
• RDS-TMC data on traffic jams, construction works or accidents are visualised as a WMS layer and taken into account when routing.

Currently we support only the test areas Bavaria and Northrhine-Westphalia in that case. The TMC data has been integrated through a service chain comprising:

• OGC SOS (Sensor Observation Service),
• a OGC WPS (Web Processing Service) and a
• OGC WFS-T (Web Feature Service- transactional)
• Accessibility Analysis Service (AAS) – The AAS calculates a polygon representing the area that is reachable within a certain time distance based on a street network around a given location.
• A OGC WMS (Web Map Service) with SLD support provides an alternative to the usual OSM renderer (such as Mapnik/OSMRenderer) for visualizing the OSM data of the selected countries
• Internally we use a OGC WFS (Web Feature Service). Within that the OpenStreetMap data has been structured thematically in semantic layers - in contrast to the simple OSM data model. This means that the OpenStreetMap data can be accessed through GML and used in further SDI or GIS applications.
• The relevant metadata will be inserted into an OGC CS-W (Catalogue Service Web).
• A OGC WPS (Web Processing Service) for calculating height profiles of the calculated routes has been realized based on SRTM DEM data and will be integrated into the Website, soon.

This demonstrates to our knowledge the first public live application of a Sensor Observation Service in combination with an OpenLS Route Service and an OGC Web Processing Service and other OGC Services within a mass-market application based on open user-generated geo-content – thus combining data from real sensors and “citizens as sensors” (Goodchild) in an OGC way. Currently we use only the TMC data for Bavaria, but we investigate the possibilities to include also further TMC information for whole Germany in another step.

OpenRouteService.org currently offers a end-user oriented website with an interactive map, there are also first prototypes of mobile clients, but we plan to also make the services available as OGC-web services, that can be used through http-based xml-requests as specified in the OGC OpenLS specification. This will allow developers to use these services in an open and interoperable way easily within their own applications. For further information please feel free to contact us.

All mentioned OpenLS services and WPS processes have been implemented by the Research Group Cartography, Department of Geography, University of Bonn.

Univ. of Bonn, Dept. of Geography, Research Group Cartography

Prof. Dr. Alexander Zipf

zipf@geographie.uni-bonn.de