From OpenStreetMap

RoadNet

Generate GeoJSON Data

from mosstool.map.osm import RoadNet
object = RoadNet()

1. Download raw OpenStreetMap data

   • object._get_osm()

2. Remove duplicated ways and nodes

   • object._remove_redundant_ways(), object._remove_simple_joints()
   • In cases where there are multiple roads connecting nodes, if it is a two-way road, keep it as a two-way road; if it is a one-way road, only keep the shortest one.
   • Delete simple nodes with only one incoming and one outgoing road, and merge the incoming and outgoing roads together. (Short merges into long)

3. Transform all roads into one-way road

   • object._make_all_one_way()
   • Splitting two-way roads into two one-way roads going in opposite directions.

4. Remove isolated roads

   • object._remove_out_of_roadnet()
   • Remove isolated ways outside the largest connected component of the road network.

5. Build junctions

   • object._init_junctions(), object._merge_junction_by_motif()
   • Initialize junctions based on the connectivity of nodes, so that every node connected to more than 1 way is considered a junction.
   • Identify fixed patterns in the road network topology and merge them into a single junction.

6. Delete redundant units

   • object._clean_topo()
   • If there are multiple roads connecting between two junctions, only the one with the most lanes and the shortest length will be retained. If a junction only has two roads, one entering and one exiting, then the junction will be removed and the two roads will be combined.

AOI

Generate GeoJSON Data

from mosstool.map.osm import Building
object = Building()

1. Download raw OpenStreetMap data

   • object._query_raw_data()
   • Ways that constitute AOIs independently are separately classified as ways_aoi. Ways that require relation descriptions are classified as ways_rel.

2. Make polygon AOIs

   • For ways_aoi, each way contained represents a closed loop shape without any inner shapes, directly serving as the shape of the AOI.

   • For ways_rel and the described relations:

     • If the number of external edges is greater than 1

       • If there are multiple closed loop edges and no open edges, take the union of all the edges.

       • If the union result contains multiple polygons, each polygon becomes a separate AOI.

       • If the union result is a single polygon, it becomes an AOI.

       • If there are no closed loop edges but there are open edges:

         • Connect these open edges. If a unique polygon can be formed, it becomes an AOI.

   • If there is only one external edge:

     • f this edge forms a closed loop (i.e., it is self-contained), the polygon formed by this edge becomes the shape of the AOI.

POI

Generate GeoJSON Data

from mosstool.map.osm import PointOfInterest
object = PointOfInterest()

1. Download raw OpenStreetMap data

   • object._query_raw_data()
   • Ways that constitute AOIs independently are separately classified as ways_aoi. Ways that require relation descriptions are classified as ways_rel.

2. Make polygon AOIs

   • For ways_aoi, each way contained represents a closed loop shape without any inner shapes, directly serving as the shape of the AOI.

   • For ways_rel and the described relations:

     • If the number of external edges is greater than 1

       • If there are multiple closed loop edges and no open edges, take the union of all the edges.

       • If the union result contains multiple polygons, each polygon becomes a separate AOI.

       • If the union result is a single polygon, it becomes an AOI.

       • If there are no closed loop edges but there are open edges:

         • Connect these open edges. If a unique polygon can be formed, it becomes an AOI.

     • If there is only one external edge:

       • f this edge forms a closed loop (i.e., it is self-contained), the polygon formed by this edge becomes the shape of the AOI.