Relative Elevation Nodes (REN) Coordinate system: 4326 - "WGS 84" Abstract: Relative elevation differentiates coincident nodes of varying elevation and outlines relationships between street segments on different planes via node-and-segment connectivity. Relative Elevation Nodes (REN) are a work-around for inherent limitations when navigating through three-dimensional street networks represented on the two-dimensional plane (i.e. computer screen). REN help to establish routing options and are particularly useful where complex overpass/underpass structures exist because they indicate street segments as being on different road-levels; where on the computer screen all streets appear to be connected. The REN layer, coupled with the Turn Restrictions Table (TRN), generates the most accurate routing. Attributes contained in this file include Relative Elevation, Intersection, Latitude & Longitude. Note: In 2012, there was a datum change from NAD83 to WGS84.

Additional Documentation

• Metadata Information

  Language: eng; CAN

  Last Update: 2015-06-24

  Metadata Contact:

  Scholars Portal, Ontario Council of University Libraries Toronto Ontario, Canada

  http://scholarsportal.info

  Contact Instructions:

  gis@scholarsportal.info

  Metadata Standard:

  ISO 19115-2

• Citation Information

  
  
  

  Series

  Name: CanMap RouteLogistics

  
  

  DMTI Spatial Inc. Markham Ontario, Canada

  Themes or Categories of the Resource: transportation

  Keywords:

  Elevation, Relative Elevation, Node, Intersection, Dangle, Dead End, Road Levels, Connectivity, 3D, Overpass, Underpass, From Node, To Node, Latitude, Longitude, Turn Restriction, Physical

  ROADS

  Roads, Road transportation, Réseau routier, Transport routier

  Place Keywords:

  Continent > North America > Canada

  Purpose:

  A nation-wide point file consisting of all nodes and their corresponding elevation.

  Dataset Language: eng; CAN

  Status: completed

  Update Frequency: quarterly

  Spatial Representation Type: vector

  Processing Environment:

  Native Dataset Environment: Microsoft Windows 2000 Version 5.2 (Build 3790) Service Pack 2; ESRI ArcCatalog 8.3.0.800

  Extent

  West Longitude: -141.001449

  East Longitude: -52.623656

  North Latitude: 82.514468

  South Latitude: 41.436108

  
  

  Supplemental Information:

  Starting with v5.1 the existing node layer (NDE) containing only To and From Node information will no longer exist. Instead, the Relative Elevation Nodes (REN) layer was created, a layer containing the To and From Nodes, their associated co-ordinates (Latitude and Longitude) and whether or not they exist at an intersection (True or False). The reasoning behind creating this base information prior to the relative elevation nodes creation is to prevent the generation of two separate Routing products. Relative elevation is a new constraint has been added as an enhancement to the previously existing node point layer. The basis of this enhancement is to mimic the existing turn restriction table, on a per release basis, to indicate where physical turn restrictions exist. This is done determining where turns cannot be made between two polylines that share a common end-point node, where an underpass overpass situation exists, thus creating an elevation change.

  DMTI Spatial Inc Markham Ontario, Canada

• Spatial Representation - Vector

  Geometric Objects:

  Object Type: point

  Object Count: 2462085

• Reference System Information

  Reference System Identifier

  Value: 4326

  Code Space: http://www.epsg-registry.org/

• Data Quality Information

  Scope Level: dataset

  
  

  Process step:

  Dataset copied.

• Distribution Information

  Distributor:

  DMTI Spatial Inc. Markham Ontario, Canada