Strange routing error near A3, Ripley

Map Editors Community United Kingdom
1

https://www.waze.com/editor/?zoom=5&lat=51.279107999999844&lon=-0.50769&showur=2418472&endshow
UR reports a routing here for which I can find no explanation - can you?

The reporter was heading west on Tythebarns Ln, and wanted to turn right at the end onto the A3 westbound. This is a permitted turn both on the ground and on the Waze map. There don’t seem to have been any recent updates to the map.

Waze’s route to get from Tythebarns Ln to the A3(W) was to turn left, then right onto the A247, U-turn at the next roundabout, and then left onto the A3(W)!

My normal explanation for strange routings is that it may have been trying to avoid a traffic jam, but this won’t wash this time as it didn’t avoid any road segments, just added extra.

What am I missing?

2

I suppose it is just possible that someone changed the allowed turns red (Tythebarns Ln to Entry to A3(W)) in the meantime and then back to green. This wouldn’t have changed the last editor on any of the segments. But I doubt it even if it is the obvious choice (students of logic please note Ripley is close to Occam). Should lock the ramps up to L3 though.

3

As the original reporter, I also had a look at the time. I’ll try again this week and see if I have the same problem.

I was coming down from Cobham via Ockham and there are about 5 different routes back through Ripley, and I has heard of an accident over the radio that I was avoiding so had a specific route that was this one that I was driving while waze was running, but ignoring it because i couldn’t force the route I wanted as it was all nasty back roads.

One of those options would have had that roundabout on the route , so waze may have route back to the key point instead. May well be a waze app bug instead!

I’ll actually take a screen shot if it happens again!

4

Any issues like no network connection? Did you make any changes on the map when you looked?

Sent from my GT-N7100 using Tapatalk

5

The area has rather poor network coverage, and i know that it does occasionally go to a red bar across the top, and given the number of times Waze was trying to get me to hit a different junction it was doing a fair amount of re-routing.

I didn’t make any changes when i looked, so the map’s not been changed at all.

We’ll just leave it and see if it happens again.

6

Hi ditchi.

This happened again yesterday, first time I’ve taken this route this year, and appears to be caused by a reroute when I didn’t take the route waze suggested.

Note the no signal in the top right

7

Weird!

Waze is certainly capable of routing that way correctly, without the diversion to the roundabout.

However, I have noticed in other places that the phone app routing is nothing like as good as the server routing. If the phone signal gets lost but there is no need to recalculate the route, everything is fine. But once the phone router gets involved, the route chosen is often further, and the turn instructions are sometimes wrong (i.e. it has a different derivation of instruction from angle, road name and priority of roads).

I think your explanation of navigating to a key point to get you back onto the route it chose earlier, and then navigating “sensibly” from that point, may well be correct.

Might be worth reporting to Waze HQ to see what they think?

8

Yeah, I’ll do that, and send the app logs as well. I raised a UR as well when it first did this route, implying I did have some form of connectivity, so if you find it first can you mark it NOT FOR CLOSURE and point at this thread?

Thanks.

9

Discussing this with Natali at Waze Support at the moment.

10

You might like to mention the strange deviations on this thread as well. The more examples, the better chance the Waze programmers have of spotting the common theme that triggers the bug.

11

Have done so.
Full email:

Hi.

Since i’ve mentioned that i’m talking to you about this, i’ve been asked to point you at this forum as well:
https://www.waze.com/forum/viewtopic.php?f=55&t=95245
There are a few examples of wierd routing that we don’t understand, and some input would be greatly appreciated!

If you route from Ockham, Surrey ( Ockham, Woking, Surrey GU23, UK) to Petersfield ( Petersfield, Hampshire) at any time of day, you correctly get a route that travels through TytheBarn lane (https://www.waze.com/livemap?zoom=15&lat=51.28299&lon=-0.50056 ) to the "Entry to A3 (S) via this node( https://www.waze.com/editor/?zoom=6&lat=51.27904&lon=-0.50881&showur=2418472&endshow=&layers=133&nodes=127495293&env=row ), meaning that you get told to turn RIGHT at that node at any time of day - So all happy.

However, when driving from Cobham (Cobham, United Kingdom), to Petersfield (Petersfield, Hampshire) you don’t get this route, you get one that’s close, but you can just drive a mix of the routes by going from cobham via this route: https://www.waze.com/editor/?zoom=2&lat=51.30072&lon=-0.42469&showur=2418472&endshow=&layers=133&env=row&segments=121581192,121580413,206131788,163139736,121580917,121581594,121581448,121581363,121581366,164003734,121579776,121578609,184234454,184234207,184234208

So, plan a route from Cobham to Petersfield at 16:00 GMT, but ignore waze’s route to the A3. Start driving from Cobham to Ockham, and waze tries to redirect you back to the old route. Eventually it routes you through Ripley (route, as partially selected in the Editor) here

If this is continued to be ignored by driving south along hungry hill lane, you get a modified route here: https://www.waze.com/editor/?zoom=2&lat=51.28868&lon=-0.49353&showur=2418472&endshow=&layers=133&env=row&segments=121579841,168339151,179977154,253907792,165027777

Keep driving south, and it decides to route finally via TytheBarn Lane and the “troublesome” node again (https://www.waze.com/editor/?zoom=6&lat=51.27904&lon=-0.50881&showur=2418472&endshow=&layers=133&nodes=127495293&env=row ) - But waze tells you to turn LEFT, go across the A3 to a roundabout, do a 180 degree, and then go back through the same node as can be seen in the image on the forums here https://www.waze.com/forum/viewtopic.php?f=55&t=74408#p778714.

Somewhere along this route ( but I don’t know exactly where, hence the hope for the debug logs) we can drop out of network connection, so routing must rely on the internal routing algorithm, which appears to have a bug in it, as it doesn’t detect the ability to turn right at the “troublesome” node.
So, yes, it’s a convoluted path to achieve this, and its quite possible a WONTFIX bug as it’s a compromise by a specific performance compromise of a re-route while disconnected, but thought it best to ask the question! I hope that clarifies the issue a bit more.

Yours,

12

Hi,

I think you can add This one as well.
Whilst in livemap you get alternatives this route is suggested.

Des. . . :wink:

13

Des, this example is not the same, and is probably just due Waze thinking the other way is quicker.

The previous examples show routes that go the wrong way, do a U-turn at a roundabout, and then come back to the same node. This has been seen before, where left + u-turn can be quicker than a right turn. This can be easily solved by disabling U-turns, but not where there’s a roundabout.

14

Going back to the original post of this topic, there’s no way that left + (eventual) roundabout U-turn is ever going to be quicker than a simple right at this particular junction.

15

And i’ll concur with that. The live map data supports this, as i’ve previously done a test route at every time of day to ensure that it wasn’t an underlying data problem.

16

HI,

No prob. :slight_smile: I’ll go crawl under a rock… :smiley:

Des. . . :wink: