→Major_roads/Main: Clarifications and updates to policy, approved by AOTB 12/5/2016
These are the general guidelines for elevation in Idaho:
* Drivable and non-drivable segments are handled the same way with elevation.
* Set elevation to
Ground on all non-tunneled segments that are not passing over /beneath another segment or waterway. * Only segments that "cannot see the sky" should have negative elevation (i.e. tunnels).* Only set elevation as high as necessary.
** Elevation of overlapping segments should be set relative to each other, with the lowest segment as Ground (unless a tunnel).
* 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.
* [[Elevation_-_bringing_the_Seagull_to_Australia|"Seagull"]] guidelines apply to elevation in Idaho.
** Bridges should be cut at the start/end of the bridge.
** Tunnels should be cut at least 15m '''before''' and '''after''' the tunnel, to allow time for the GPS to regain signal.
** Do not cut segments for elevation purposes if the bridge/tunnel starts/stops within 60m/200ft of an existing junction.