|
|
(3 intermediate revisions by the same user not shown) |
Line 1: |
Line 1: |
| === True Elevation ===
| |
|
| |
|
| Wisconsin uses the concept of True Elevation on segments within the State. The use of '''True Elevation''' (TE) is to better represent segments in relationship with its surroundings/ground level. Most segments should have an elevation of ground unless they pass over another segment, waterway, or natural feature. '''Drivable and non-drivable segments are handled the same way with elevation'''.
| |
|
| |
| '''The practice of True Elevation is NOT observed on Freeway or Ramp segments.'''
| |
| For freeway and ramp segments please reference national guidance [[Creating and editing road segments#Road elevation|Road Elevation]] and [[Overpasses, Underpasses and Bridges]].
| |
|
| |
|
| |
| '''Definitions'''
| |
|
| |
| ''Bridge''
| |
|
| |
| * Segment travels over another segment (also known as overpass)
| |
| * Segment travels over a river or body of water
| |
| * Segment artificially elevated to pass over ground level objects and natural features.
| |
|
| |
| ''Tunnel''
| |
|
| |
| A tunnel is any road segment that is underground and thus the GPS reception is inconsistent.
| |
|
| |
| '''Implementation'''
| |
|
| |
| * Elevation of overlapping segments should be set relative to each other, with the lowest segment as Ground (unless that segment is a tunnel).
| |
| * Only elevate/lower the actual bridge/tunnel section of the road.
| |
| * Bridges should be cut at the start/end of the bridge where the land falls away. You can usually see guardrail at the start/end of the bridge section. Also the pavement type may change (Asphalt to Concrete for example).
| |
| ** Do not cut segments for elevation purposes if the bridge starts/stops within 500ft(150m) of an existing junction.
| |
| **Do not create a segment less than 200 feet(60m) in length
| |
| ** No need to elevate segments over every small creek or box culvert. Only elevate over significant waterways or natural features.
| |
| * Only set elevation as low/high as necessary. For example, no segment should be Elevation +2 unless it passes over another segment with Elevation +1.
| |
|
| |
| * Tunneled segments shall have lower elevation, relative to ground and ''Tunnel'' should be checked.
| |
| * Only segments that are actually '''underground''' should have the negative elevation.
| |
| * Tunnels should be cut at least 15m/50ft before and after the tunnel, to allow time for the GPS to regain signal.
| |
| * '''The use of common sense is paramount in using True Elevation.'''
| |
|
| |
|
| |
| ''NOTE: If you use the Bridge tool to join segments, be aware that it raises the elevation of the joined segment. Lower the joined segment as appropriate.''
| |