Level3 California - Santa Clara

Map Editors Community United States US Unlock And Update Requests
1

My Level: 1

Map should be updated to indicate the U-turn is allowed on Montague Expy at this intersection - (actually in both directions). Street view clearly shows the street sign markings allowing the u-turn.

Thanks

bschloby

2

I have allowed a U-turn both directions, but keep in mind that Waze currently doesn’t say “U-Turn”. It will give the command to take a left.

3

Ok, thanks - just trying to help out a few of the UR’s in the area that gave out of the way directions.
Thanks!

4

Feel free to use one of the other user’s boilerplate responses for this and other things.

https://wiki.waze.com/wiki/User:Voludu2/UR#We_can.27t_do_U-turns
https://wiki.waze.com/wiki/User:DwarfLord/UR#We_can.27t_do_U-turns

5

Yeah, I was about to look at doing those replies, thanks for the boilerplates!
But then I noticed the U-turns are disallowed again!

This leads me to wonder why Montague Expy is drawn as a single two-way street, rather than a pair of one-way streets. Sure - it’s easier to draw one vs two, but it would make U-turns (and user app driving instructions) more clear. Mission College Blvd is drawn as a pair of one-way streets, for example. Both are divided roads, and Montague is a more major road.
Anyway - it’s all locked down for people more experienced than a new editor such as myself, so I’ll leave it to others to sort out that problem.

Meanwhile, any idea why the U-turns are once again disabled? It sure leads to strange driving instructions, as you can see by looking at some of the URs there.
Thanks!

6

It’s just a lot of work to do a split and have it come out right. DwarfLord is who’s last edited those. You might PM him about it.

I’ve got a number of URs in Seattle complaining about split roads giving the double left command to do a U-turn. We can’t win until the TTL gets a fix, and there’s no telling when that will be.

7

First, a big thank you to both of you for working URs in the area. When I started editing about a year ago, nobody was doing URs in the South Bay!

In general, it helps to remember that the Waze map is logical, not literal. Of course we need good positional accuracy, but it is not a goal in itself to match the satellite image exactly. Sometimes attempting to do so is counterproductive.

The case of “to split or not to split” presents us with quite the rabbit hole. Controlled-access freeways: definitely. Roads divided by a legal or physical median: maybe.

Before I go into this in more detail, remember that the burden of proof is always on splitting. That is, when in doubt, do not split. The flip side is that once the deed is done, the burden of proof shifts somewhat because it is a dangerous PIA to unsplit roads and if they seem to be working OK the general attitude is to leave them alone.

That may explain why you might encounter roads split in Waze that don’t seem to qualify. It’s not necessarily that they are shining examples of roads that should be split. They may have been split long ago by a bored brand-new editor who lost interest shortly thereafter but the legacy lives on.

The primary questions to resolve the “maybe” are:

  • Are there many destinations along the road that one reaches directly from the road and not via a limited number of cross-streets and/or parking-lot roads? For example, El Camino Real is filled with wall-to-wall destinations accessed directly from the road. The combination of all those destinations and the uncrossable median makes El Camino a must-split. Likewise divided roads in residential neighborhoods where houses line the divided road.

  • Could the driver get far enough from the segment that Waze loses lock? If the lanes are very far apart this can happen, but you have to get a long way from a segment before Waze decides not to snap you to it any more, especially if you are following a route. HOWEVER, if there is anything resembling a frontage road along the main road, that changes the equation, as Waze may snap you to that road if you are closer to it, especially if there are GPS errors.

NOW we come to U-turns. Waze cannot tell you to do a U-turn anywhere; it’s missing the navigation directive. So all those U-turn icons at every intersection in WME are, at present, purely decorative. As dude463 said, all we can do is a bowtie u-turn “left” or a box/h junction u-turn “left, then left”.

So in rare cases, we have to “hack the map” and split a road for the sole purpose of working around Waze’s lack of core functionality. One day, if and when Waze implements this core functionality, we can go back and undo these hack splits. Yay!

Finally, regarding the U-turn indicator getting changed. When correcting corrupt turn restrictions in an area, a common practice is the ‘qw’ key sequence to reset a junction to all green, followed by careful inspection to see if any turn restrictions should be red. This process doesn’t destroy time-based turn restrictions, but it does destroy U-turn information. That’s probably what happened here, as I have been applying FC in this area and finding lots of issues. I regret if I have been unwittingly changing U-turn settings! It doesn’t matter what they’re set to and we have no timetable for when it will matter, but I agree more care with them is needed since the functionality may indeed come some day.

I will take a hard look at this intersection and see if maybe it does need to be hacked (oops, split) if U-turns are frequently needed there.

(CORRECTION: It shouldn’t matter at present how U-turn restrictions are set. But there is some evidence that, when recalculating a route, the routing server may actually look at the U-turn setting although it isn’t supposed to right now. Rather than disable U-turns to guarantee this can’t happen, Waze asks that we alert them to instances of such events.)