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Re: Routing errors in London

Posted: Mon Jul 22, 2013 4:51 pm
by dknight212
This is really helpful, thanks a lot.

Do you have any ideas as to whether this is a map or an algorithm based problem?

Re: Routing errors in London

Posted: Tue Jul 23, 2013 12:15 pm
by dknight212
Chris

This is really useful work you're doing here. Thanks so much.

David

Re: Routing errors in London

Posted: Tue Jul 23, 2013 3:18 pm
by dknight212
Ok testing some E-W routes:

A13 Alfred's Way (Barking) to A316 The Avenue (Richmond) = fail

coming in a bit to Mortlake I get two routes but both drop a bit short over the northside of the river. One of these uses the North Circular.

a bit more to the east side of Putney and we get two successful routes neither of which use the North Circular.

Ditto for Chelsea.

Woolwich to Chelsea ok

Woolwich to East Sheen = fail

Woolwich to Putney is a very interesting one so screen shotted. Destination is just by Wandsworth Park but although I get two routes one drops short on the north side whilst the south of the river one actually crosses the river to end up nearer the first one than the destination!

http://ubuntuone.com/2MOJSVzK0UrqxEdybRmndl

Re: Routing errors in London

Posted: Wed Jul 24, 2013 6:34 am
by dknight212
Chris - I think you have these tests scripted now, is that right? Is it very difficult to tabulate these results so Waze HQ have an easy reference for their checking? No worries if not.

Ideally something like: start lat/lon/street, finish lat/lon/street, time of day, success/fail, distance A, distance B

Just shoot me if I'm asking too much!

Re: Routing errors in London

Posted: Wed Jul 24, 2013 11:53 am
by dknight212
Twister_UK wrote:
Something else that crossed my mind regarding the interaction between the routing algorithm and the traffic data - since the traffic data changes quite frequently at certain times of the day, I wonder if the routing code takes a snapshot of the data before starting to generate each new route, or if it just assumes that the live data isn't going to change significantly during the calculation of the new route. If the latter, then there's always the chance that during the calculations the data has changed in such a way that the intended route breaks whatever internal thresholds/sanity checking are set for the routing code.

Given that it generally seems to be the quickest route option that starts to fall short of the intended destination before the routing code gives up completely, this would tie in with it being traffic data related - the shortest route would only be affected if the road closure data got updated during the routing calculation, whereas changes in traffic density shouldn't affect it at all (it doesn't care how long it takes to get from A to B...).
Good thinking, could test by rerunning the same route several times?

Re: Routing errors in London

Posted: Thu Jul 25, 2013 9:17 am
by dknight212
A-MAZ-ING

Re: Routing errors in London

Posted: Sun Jul 28, 2013 8:17 am
by dknight212
woodvale wrote:The information that Twister is producing is wonderful, and I have no idea how it's done :? I do hope it leads to an early resolution of the problem.

Meantime, URs continue to be raised containing postcodes or addresses, presumably failed routing searches. Do we want to keep these for further evidence, or close them?

There also appears to be a spate of "off and on" routings at M25 junctions south of London (I haven't looked elsewhere 'cos that's outside my area), with two in the last three days at J6, Godstone. Are these likely to be related? I know it shouldn't happen - in the US, it appears to be illegal - but it does. Is there a known solution to this problem?

[EDIT - grammatical correction]
I've got an idea how it's done but am still amazed at the skill of some in the UK Waze community. Does anyone have any concerns that Waze HQ won't like calling the routing server so frequently?

The postcode errors do annoy me (and I'm sure the users are annoyed too). I presume most of them are failed routes but having seen some of the replies to UR comments I'm sure some of them are also user error. I'd continue to follow up the errors with each user as you have been doing, at the very least users do get some feedback.

The on and offs seem to be getting more frequent. Not just on motorways either. I presume Waze has somehow adjusted the algorithms and they will have to tweak them some more. Perhaps we should start up another thread (with screenshots).

Re: Routing errors in London

Posted: Mon Jul 29, 2013 3:30 pm
by dknight212
Twister_UK wrote: And quite frankly, if Waze are concerned about one extra routing request per minute, then we've got more to worry about than the number of incomplete routes being returned.
That's what I would have thought but you never know. It will be so useful for them to see this thread.

Sent from my GT-N7100 using Tapatalk 4 Beta

Re: Routing errors in London

Posted: Wed Jul 31, 2013 4:33 pm
by dknight212
Chris - any updates on this?

Re: Routing errors in London

Posted: Sun Sep 08, 2013 10:18 am
by dknight212
shirapashu wrote:Hi,

In order to recreate the problem, if you could have another test and share the following info with us:

1. Starting and ending points.
2. Time and date.

Thanks,

Shira
Shira, are the data in the zip file above not sufficient? See the csv files in particular.