Off and On

Map Editors Community United Kingdom
1

Thought it might be useful (or at least give us a space to vent frustrations) to pull together a collection of routing off the main highway and back on again. Getting quite a few recently. Here’s M25 (ACW) at J11:

https://world.waze.com/map-editor/?zoom=4&lon=-0.50811&lat=51.37566&layers=BFTFFTTTTTTTFTTTTTFTTTTFT

UR Guidelines
Update Requests (UK)
2

Junction 8 (sorry for the scaling)

https://world.waze.com/map-editor/?zoom=4&lon=-0.1955&lat=51.25934&layers=BFTFFTTTTTTTFTTTTTFTTTTFT

3

Junction 6

https://world.waze.com/map-editor/?zoom=4&lon=-0.06298&lat=51.2588&layers=BFTFFTTTTTTTFTTTTTFTTTTFT

4

Needless to say:

  • these junctions usually route fine
  • we don’t know if the users have long or short journeys
  • sometimes off and on can in fact save time, but it’s quite rare (I’ve experienced it once)
5

Something to add to this subject. On Wednesday morning I routed from St. Neots in Cambs to Barrow in Cumbria. About 5 hours worth of route. As I came off the end of the M6T I had instructions for coming off at J16

https://world.waze.com/editor/?zoom=4&lat=53.06756&lon=-2.33901

I recalculated route and the J16 vanished.
I’m assuming it’s something that happens on longer routes only, as the off and on again penalties will have less of an impact over a long distance. In the past I’ve had off/on occurring on the M5 on routes down to Cornwall. Again this is routes of 5 hours+

6

Routing is supposed to stick to the Motorway if the road name and type continues uninterrupted either side of the junction. Worth seeing if our hacks to force ‘keep rights’ are leading to these off-and-on-again routing.

via mobile

7

Certainly saw them before on the M25 but perhaps the frequency has increased since.

Sent from my GT-N7100 using Tapatalk 4 Beta

8

Don’t think it’s related to the “keep rights”. It’s not doing it on the junctions where they occur anyway.

I did think the other day, is it something in the algorithms not allowing you on freeway roads for longer than x time?

9

HQ have released some information about when routing will avoid a ‘detour’ from a major road.
Here’s a paraphrase of what they said, as I understand it, of how to prevent detours from happening:

  • Detours go between two segments with the same name, and with the same road type via a different road type.
  • Freeways and Major Highways: Detours are avoided if they are less than 5km.
  • Minor Highways: Detours are avoided if they are less than 500m.
    This means, I think, that a) our hacks for keep left/right are probably breaking this mechanism,
    and b) large junctions on minor highways may have detours longer than 500m. A typical GSJ has at least 600m of ramps, not counting the roundabout.
10

Possibly it is (b). I can’t find our hacks on dknight’s examples so it should not be (a).

Btw, I maybe wrong. I thought the announced algorithm is only implemented on NA server, not yet on INTL server.

11

It can’t be b) either as all the above examples are on Freeways. However, either of those two things could be the cause in other cases.

I didn’t see any indication that this was NA only, but maybe I missed it.

12

:oops: :oops: :oops: :mrgreen:

My understanding from this thread. The new algorithm is testing on NA. I’m hoping it was on INTL but my few routing issues do still exist :cry: so I assume it is not on INTL yet.

13

I didn’t think these rules about detours are related to the new algorithm that’s being tested.

14

I don’t understand. All the off/on detours we find are off motorways, and all of them are under 5km.

15

Well, if we’re still getting off-and-on-again routing, and the detours meet all of the criteria listed above, then we still have a problem for Waze to fix.

Any more examples?

16

So our hacks for keep left/right might interfere because we have a segment progression of eg:

M25 (CW) - blank - Exit to …
or
M25 (CW) - blank - M25 (CW) … [through junction] … M25 (CW)

Because of the blank segment (or one with extra space or whatever), Waze doesn’t clock this is a potential detour and hence then doesn’t apply the extra logic to smooth them out.

Is that right?

17

Yes, that’s my thinking.

18

I’m not so sure, as I read it that it’s the detour route that’s checked, not the straight on route. A detour for a mtoroway with hack would go M25 (CW) - Exit/roundabout/entry - M25 (CW) - and change road type.

19

Problem is that with some hacks, the segment preceding the exit junction is unnamed, so Waze won’t check the detour against the other requirements, and will therefore consider it as a possible route.

On a related note, we should ask Waze to fix the keep left/right instructions so that we don’t need to hack the map.

20

Yes, but I don’t think that’s an “approved” method any more.

There goes that flying pig again!