Road Elevation
In general, North Carolina only follows “True Elevation” to the extent that negative elevations should only be used for tunnels, and does not follow “Seagull” elevation rules, with some exceptions as described below. This is due in part to issues experienced with exceptionally short segments, and to our state’s unique closures system, where most closures are handled by editors instead of Waze Partners.
General Principles
- Drivable and non-drivable segments are handled the same way with elevation.
- Set elevation to Ground in most cases.
- Only segments passing over other segments shall have higher elevation, relative to ground.
- The entire segment should be elevated between existing junctions with other segments.
- Do not cut segments at the start/end of a bridge (see exceptions below).
- Do not increase elevation on segments passing over water or any other bridge that does not cross other segments (see exceptions below).
- Elevation of overlapping segments should be set relative to each other, with the lowest segment as Ground (unless a tunnel).
- Only set elevation as low/high as necessary (i.e. only set elevation to 2 if passing over a segment set to 1)
- Only tunnel segments should have negative elevation.
Exceptions, to allow for proper closure placement
- If a navigable destination (i.e. house number or place entry point) exists on a segment that would be elevated, the segment should be cut at the start/end of the bridge/actual elevated portion (unless another junction is located within 60m/200ft).
- Bridges over water on rural, two-way segments [may/should] be mapped with cuts at the start/end of the bridge (unless another junction is located within 60m/200ft), and the elevation raised by 1 to suppress “unneeded junction” warnings from scripts.
Reminders
- 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.
- Tunnels should be cut at least 15m/50ft before and after the tunnel, to allow time for the GPS to regain signal, and must have the “Tunnel” checkbox selected in addition to negative elevation.
Examples
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Good: This bridge was cut because it is a rural, two-way segment over water (it would also qualify under the first exception for nearby destinations, due to the driveway to the south).
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Good: This bridge has destinations on either side of it that should remain accessible in the event of a closure.
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Good: This ramp is a single segment with an elevation of 3, because the off-ramp from I-540 W to Capital Blvd (labeled #1) must be at elevation 1 due to crossing over Triangle Town Blvd (the LS at the southeast corner), which makes the on-ramp from Triangle Town Blvd to I-540 W (labeled #2) at elevation 2, due to crossing over the aforementioned off-ramp.
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Good: This bridge is cut at the west end, due to the presence of a destination (HN), but not cut on the east end due to the nearby junction (note: screenshot utilizes the HN Navpoints script to show where HNs fall on the segment).
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Bad: This bridge should be cut at its west end due to the presence of the cemetery and its HN; the east end should not be cut due to the nearby junction (note: screenshot utilizes the HN Navpoints script to show where HNs fall on the segment).
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Bad: Bridges on freeways should not be cut. Instead, the entire segment between the ramps should be elevated in each direction.
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Bad: A bridge over a highway between two ramps does not have any destinations and should be one elevated segment:
NC Update Requests Proposal
North Carolina follows the national guidance for Update Requests (URs). We encourage editors to use their best discretion when handling URs, particularly with regards to timing of responses, the use of reminder messages, and team handling.
Best Practices:
- Most editors in North Carolina follow the 1-4-8 open-reminder-close timeline for handling URs (sometimes referred to as 0-3-7), where an initial response is sent on Day 1 (with a goal of responding within 24 hours of receiving the UR), an optional reminder message is sent on Day 4 if no response is received (3 days after the UR is received) , and finally the UR closed on Day 8 if no further response is received (7 days after the UR is received, and at least 3 days after the last reminder or response is received).
- It is best practice to allow reporters 3 days to respond to any reply sent, even if this exceeds the typical 7-day close timeline.
- Reminder messages are discretionary in North Carolina. Most NC editors use them for the majority of URs, but there is no mandate to do so.
- Team handling is encouraged but not mandated in North Carolina. We encourage editors to become familiar with and build a rapport with their fellow NC editors, in particular Area Managers and State Managers, so that you are on the same page regarding UR handling methods and preferences, such as sending reminder messages on another editor's UR. If another editor has firsthand knowledge of the issue and can make the necessary corrections to the map to solve the reported issue, they are free to do so.
- The use of standardized comments such as those found in the URComments-Enhanced script may be beneficial, particularly to editors handling URs for the first time; however, there is no standardized list for NC or SAT, nor is there a mandate to use standardized comments of any form. NC editors are encouraged to tailor their responses to the specifics of the UR in question, which can lead to better response rates from reporters.