OSM

OpenStreetMap is a worldwide project with the aim of collecting freely available and editable geographic data, in particular roads, cycle paths and footpaths.

Well over 20 million kilometres of roads, cycle paths and footpaths have been mapped, by tracing aerial imagery and by contributors surveying on the ground with GPS devices.

Content

The primary entity in OSM is the road or path segment. Per segment, attributes are recorded such as road type (highway=*), name, and whether it is one way. These segments are suitable for network analysis. Alongside road segments, OSM also distinguishes railways, natural features and buildings.

Availability

• OSM can be consulted online via www.openstreetmap.org or www.openstreetmap.nl.
• The data can be downloaded in various formats from several sites, including download.geofabrik.de.

Strengths and limitations

OSM is the default choice for accessibility modelling because it is global, free, and the only widely available source that also covers cycling and walking networks. Two caveats apply.

• Completeness varies geographically. Urban Western Europe is close to exhaustive, while rural areas in some countries are not. Verify against a reference for the study area rather than assuming.
• Tagging is a convention, not a schema. Speed limits, access restrictions and surface types are inconsistently filled and occasionally implausible. Implausible values need correcting before they become travel times, see Travel speeds per mode.

Use

We use OSM for accessibility analyses.

An average travel speed per road type has been determined in collaboration with the Department of Spatial Economics at the VU Amsterdam. Combined with the length of the road segments, this yields travel distances and travel times from, for example, dwellings to various types of facilities.

OSM is also the sole network source for the worldwide network model, which builds a routable car network per continent for the entire planet.

Examples

1. Using OSM and the BAG, a PC4 travel time matrix was produced for the VPRO multimedia project Nederland van Boven.
2. Using OSM and the BAG, road distances were calculated from every building in the BAG to the nearest primary school. The results were made available to EduGIS.

Alternatives

• NWB, for car networks in the Netherlands
• Network data sources, full comparison