And I just saw this post from Alan discussing the junctions with RR crossings [underline added by me].

AlanOfTheBerg wrote:Junctions only impact routing until segment speed data is captured, then the junction "penalty" goes away. Waze doesn't need to have a project to identify RR crossings, because with a junction, the Waze speed capture does the rest automatically. Long delays at that junction will be collected and aggregated by the 10min/30min timeslice with all other stop light and stop sign data.

I have several segments of 50 to 100km, they did not turn into ghost segments, and waze is able to route on them. But I'm not that their average speed will be correctly calculated by waze as there is very few drivers on those roads, most of the time no network (as it is in Sahara) so I don't know if waze will be able to calculate the average speed, I'm waiting for a new driver on it, the last one was 3 months ago .

One problem with long segments is traffic jam detection.
If a segment is 20km long and there is some traffic jam on 3km, I think it will be hard to detect, and if not detected waze will use the known average speed of the segment and not the current speed due to the traffic, don't you think?

The other problem is to know what happens to the average speeds that waze knows if the segment geometry is changed, the segment splitted ...

Because if you loose 10 minutes on 1km it is important, if you loose 10 minutes on 7 km it is not so important. If it is under the threshold to detect a traffic jam, waze will use the known average of the segment and ignore that you loose 10 minutes.

Maybe, and on very long segments, I don't expect a lot of traffic jam as they are not in urban area usually.
There is still my other problem on traffic data on very long segments if the geometry is changed (and also because I don't know what happens with erratic network connections.

But if the segment is very long it can take one or two hours (when the segment is 100km long), and I'm not sure how waze will do if the next intersection is at a place where there is no network ? It will never get the speed of the segment ?

ncc1701v wrote:

kpouer wrote:The other problem is to know what happens to the average speeds that waze knows if the segment geometry is changed, the segment splitted ...

It's better to retain existing segments if you can, no?

Right but I'm also mapping in Africa, there is no basemap. So I'm drawing major roads first. For example I created the beginning of Trans-sahara highway, already 2400km. Usually it's very straight lines in the desert. Then I may add some crossing roads if necessary so I have to split sometimes, or move the road because in some places I had to assume it's position without GPS dot and without satellite view.


@bgodette, thanks for your answer, so I can split or merge segments without problems. But do you have an option on very long segments ? If the segment is too long like 50km, I'm affraid that waze may not be able to get any valid time as too many problems can occur (like having no network at the beginning of the road or the end, or things like that).

In fact I don't drive here, I go sometimes in the north, but never in the south, so I'm mapping with the roads that users create or only use satellite photos (of course it's not the best but as I am the only mapper in those countries since 3 years it's better than nothing).
Recently I found a guy who did that trip in 3 days. He created the road but it is mostly like this and I have to join roads

@bgodette, that's good news. During Barcelona meetup we were told that they were able to detect traffic on a sub-segment but not highlight a sub-segment yet. If they can now it's a good evolution, maybe we should ask if it is available on all servers.

I had some problems editing segments of up to 80 km in length. I seems that they all ended up as ghost segments.
Running mostly north / south I redid & split them down to what would typically fit across the height of the screen at max zoom, which is about 18 to 22 km max.
I'm still worried that this is too long and the same thing might happen.
Just as a test, I removed a node and re-saved today. Still no problem on a 22292m segment.

If I add long stretches now, I hardly go above 10km too.

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