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link

  • description A link is an edge in a network, defined by the nodes it travels from and to. It may have associated geometry information. Links have three types of attributes:
    - Those that define the physical location of the link (e.g., shape information, length, width)
    - Those that define the link's directionality: from_node, to_node
    - Those that define properties in the direction of travel: capacity, free flow speed, number of lanes, permitted uses, grade, facility type
  • path link.csv
  • schema
    • missingValues ['NaN', '']
    • primaryKey ['link_id']
    • foreignKeys
    • [1]
      • fields ['from_node_id']
      • reference
      • resource node
      • fields ['node_id']
    • [2]
      • fields ['to_node_id']
      • reference
      • resource node
      • fields ['node_id']
    • [3]
      • fields ['geometry_id']
      • reference
      • resource geometry
      • fields ['geometry_id']
    • [4]
      • fields ['parent_link_id']
      • reference
      • resource
      • fields ['link_id']
    • fieldsMatch subset
name type description constraints categories warnings
link_id any Primary key - could be SharedStreets Reference ID {'required': True}
name string Optional. Street or Path Name
from_node_id any Required. Origin Node {'required': True}
to_node_id any Required. Destination Node {'required': True}
directed boolean Required. Whether the link is directed (travel only occurs from the from_node to the to_node) or undirected. {'required': True}
geometry_id any Optional. Foreign key (Link_Geometry table).
geometry any Optional. Link geometry, in well-known text (WKT) format. Optionally, other formats supported by geopandas (GeoJSON, PostGIS) may be used if specified in geometry_field_format in gmns.spec.json
parent_link_id any Optional. The parent of this link. For example,for a sidewalk, this is the adjacent road.
dir_flag integer Optional.
1 shapepoints go from from_node to to_node;
-1 shapepoints go in the reverse direction;
0 link is undirected or no geometry information is provided.		 [{'value': 1, 'label': 'forwards'}, {'value': -1, 'label': 'reverse'}, {'value': 0, 'label': 'no-information'}]
length number Optional. Length of the link in long_length units {'minimum': 0}
grade number % grade, negative is downhill {'maximum': 100, 'minimum': -100} {'maximum': 25, 'minimum': -25}
facility_type string Facility type (e.g., freeway, arterial, etc.)
capacity number Optional. Saturation capacity (passenger car equivalents / hr / lane) {'minimum': 0}
free_speed number Optional. Free flow speed, units defined by config file {'minimum': 0, 'maximum': 200} {'minimum': 1, 'maximum': 120}
lanes integer Optional. Number of permanent lanes (not including turn pockets) in the direction of travel open to motor vehicles. It does not include bike lanes, shoulders or parking lanes. {'minimum': 0}
bike_facility string Optional. Types of bicycle accommodation based on the National Bikeway Network Data Template (Table 1-A at https://nmtdev.ornl.gov/assets/templates/NBN_DataTemplates_final.pdf) ['unseparated bike lane', 'buffered bike lane', 'separated bike lane', 'counter-flow bike lane', 'paved shoulder', 'shared lane', 'shared use path', 'off-road unpaved trail', 'other', 'none']
ped_facility string Optional. Type of pedestrian accommodation: unknown, none, shoulder, sidewalk, offstreet path ['unknown', 'none', 'shoulder', 'sidewalk', 'offstreet_path']
parking string Optional. Type of parking: unknown, none, parallel, angle, other ['unknown', 'none', 'parallel', 'angle', 'other']
allowed_uses string Optional. Set of allowed uses that should appear in either the use_definition or use_group tables; comma-separated.
toll number Optional. Toll on the link, in currency units. {'minimum': 0, 'maximum': 10000}
jurisdiction string Optional. Owner/operator of the link.
row_width number Optional. Width (short_length units) of the entire right-of-way (both directions). {'minimum': 0} {'minimum': 10}