Timbones wrote: 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.

Yes, but I don't think that's an "approved" method any more.

Timbones wrote: 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.

There goes that flying pig again!

Possibly - Waze does seem to be less resilient to short-term GPS glitches than other satnavs I've used - though in many of these examples the off-on route seems to be generated whilst the user is still clearly on the main carriageway.

ditchi56 wrote:Perhaps the solution is to raise the Minor Highway threshold only if the diversion involves a ramp segment?

That does seem like the makings of a rather good idea - as you say we don't want to prevent Waze from generating useful diversions, it's really only the damned annoying off and ons we're concerned about, and the one thing most/all of those have in common is that they involve the use of ramps...

Would it make even more sense if the routing penalty was only invoked if two seperate ramp segments were involved (i.e. both the off and on parts of the diversion), rather than just if a single ramp segment was involved in any way? I'm thinking there may be cases where the use of a single ramp segment (to get off OR onto the main road) would be a valid diversion, so we wouldn't want to prevent such routes from being offered as a side effect of eliminating off and ons.

And one here on the A404. Given how bad the northbound traffic gets in the morning rush-hour here I'd have just written this one off as having triggered the time-saving threshold you've mentioned above, but the UR was submitted at 2am when there shouldn't have been any traffic to speak of...

Timbones wrote:

Twister-UK wrote:And one here on the A404. Given how bad the northbound traffic gets in the morning rush-hour here I'd have just written this one off as having triggered the time-saving threshold you've mentioned above, but the UR was submitted at 2am when there shouldn't have been any traffic to speak of...

Actually, the change in road name and type here disrupts the detour avoidance algorithm. I've made some adjustments to try to get it working again.

Ah yes, how did I manage to miss that... I take it the adjustments were adding the "Stay on A404" alternate name to the segments running through the mainline of the junction?

Timbones wrote:

theMadcabbie wrote:Here is another on and off on the M4 tonight

It looks like there was a lot of traffic, so Waze was just doing what it does best, particularly if it will save 5 minutes or more...

Considering how much traffic comes off the M4 there in normal conditions to turn right towards Heathrow, I'm amazed the exit slip wasn't also bright red from the combination of normal traffic plus people being persuaded into leaving there to avoid the logjam on the main carriageway.

That, of course, is assuming this wasn't just yet another bloody annoying virtual jam with absolutely no traffic whatsoever in sight, making remaining on the main carriageway a perfectly sane thing to do.


As a general comment about off-and-on routing and other similar-ish attempts by Waze to route around traffic (e.g. all the recent spate of routes turning off the main road into a side road to do a u-turn and head back onto the main road, or routes that take you past the turning you were expecting to use, to then drive around the block and rejoin your route a short way further on etc. etc), I'd be quite happy if Waze wasn't quite so determined to save time like this, but instead gave more priority to suggesting routes that were "obvious".

I know there's always a minority of drivers who'll do anything and everything to save a few seconds here and there no matter what effect it has on everyone else around them, but I'd rather Waze didn't try turning us all into complete arseholes like that - if sitting in a queue for an extra few minutes means you aren't being asked to perform a bunch of moves that even the most hardened of rat-runners might think twice about before attempting, then that's the route Waze ought to be suggesting. Especially since more often than not, the only reason the alternate route looks so attractive time-wise is simply because Waze doesn't have enough historical or realtime data to realise that in reality it isn't going to save anything like as much time as it thinks it will.


It also feels as if these issues are related to something that Waze have changed in the routing algorithms in the last couple of months, as whilst there've always been URs raised by people who disagree with the time-saving routes Waze has come up with, it only seems to be recently that those URs are being raised for routes which really do take the biscuit as opposed to routes which actually make sense and are simply taking the users by surprise.

A316 near Feltham...

Segment naming and type looks consistent on the mainline through the junction, and no fundamental issues preventing the direct route from being offered. The only thing I did notice was the segment directionality flipping back and forth between A-B and B-A.

Would that break the detour avoidance, or is this just one of those cases where the length of the junction is enough to make it look as if the off and on would save enough time (despite what the reporter has found in reality) for it to be allowed?

And a couple of URs at M25 J14 as well...

This one looks fairly clear-cut, with the M25 clockwise segment at the northern end of the junction having a "Greater London" county name whilst the rest of them have "Surrey" - could a L5+ check and adjust as required please.

On the anticlockwise side, the same is also true in reverse, with all of the segments having "Greater London" as their county except for the one right at the southern end which is "Surrey". No URs raised here that I can see, but probably worth checking this side too to pre-empt any problems...

theMadcabbie wrote:M4 J8 / J8 - Maidenhead Westbound

This off / on is popping up every couple of days still, I can't see a reason i.e. It is as likely happen at 2am or 2pm It doesn't seem to be affected by day of week. I travel through this junction 20+ times a week - and can see no logic as to why this is happening.

Permalink

Both the main carriageway and the westbound entry slip segments here had the same street name - "M4 (W)" - which seems to be one of the things which can break detour prevention assuming that the rules listed on the US Wiki apply here too...

Somewhat surprisingly, this slip road (plus 2 of the other 3 at this junction) have been left auto-locked to L4, so I've now renamed it to "M4 > The West" - let's keep an eye on routing behaviour here after the next tile update.

jonv-uk wrote:

Twister-UK wrote:
Both the main carriageway and the westbound entry slip segments here had the same street name - "M4 (W)" - which seems to be one of the things which can break detour prevention assuming that the rules listed on the US Wiki apply here too...

Somewhat surprisingly, this slip road (plus 2 of the other 3 at this junction) have been left auto-locked to L4, so I've now renamed it to "M4 > The West" - let's keep an eye on routing behaviour here after the next tile update.

Looks like someone has been along and changed it back to M4 (W) !

Thanks, that's been put right again...