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Private transport
Private transport refers to all modes of personal transportation, including car, bicycle, and walking. For cycling and walking, the OpenStreetMap (OSM) network is used. For car travel, either the OSM or the TomTom network can be applied, both of which are parameterised.
OpenStreetMap (OSM) data are downloaded per region in shapefile format. In addition to the Dutch provinces, adjacent German regions (Niedersachsen, Düsseldorf, Köln, Münster) and Belgium are included. All extracts are merged into a single network and cleaned for overlapping geometries. Relevant attributes are extracted, such as road type, speed limit, and directionality.
Because OSM speed limits are often missing or implausible, they are corrected using empirical rules. If the recorded speed is positive and below 140 km/h, it is accepted. Otherwise, the 90th percentile speed per road type is applied; if that is unavailable, a parameterised low speed (e.g., 30 km/h) is used. For motorways with speeds below 80 km/h, the 90th percentile is also enforced. If the resulting speed remains zero, the parameterised default car speed (e.g., 50 km/h) is applied, and if still below 15 km/h, it is set to 15 km/h.
TomTom congestion data may be integrated into the OSM network. Because TomTom segments do not directly correspond to OSM segments, spatial linking is performed using a configurable search distance. To avoid mismatching motorway segments with nearby local roads, the network is first partitioned into motorways, major roads (primary and secondary), and streets.
The TomTom dataset consists of roads, junctions, historical speed networks, and historical speed profiles by time of day (morning, noon, evening) and day type (weekday, weekend, holiday). Parameters defining which profiles to use are configurable in the model setup.
After the network is completely prepared, the actual accessiblity analysis can be performed. If, for example, a OD-matrix from neighbourhood to neighbourhood has to be created. Where there are links from the origin points to the network, and links from the network to the destination points. The Dijkstra algorithm is used to find the least resistance route from each origin to each destination. Resistance could be distance, time or anything else that can be measured per link.
Object Vision B.V.