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[UK] All U-Turns Disabled

Post by Timbones
After months of requesting this of Waze, they have run a process to disable all the U-turns some time around June 22nd. This means that going forward, you should not see any enabled U-turns, and any you do come across should be disabled.

Clarification: by U-turns, we mean when a 2-way segment is connected to itself (a "self-con"), and the little U-turn arrow for a selected segment appears green. We don't mean a U-turn on a dual-carriage way, which is actually two "turn right" instructions.

Why?
  1. The client has no instruction for U-turn, so there's no reason to support them.
  2. In the UK, roads are usually too narrow to safely perform a U-turn manoeuvre
  3. Places where U-turns are safe to perform are probably mapped as dual-carriageways anyway.
  4. U-Turns at the end of dead-ends can result in odd in-and-out-again routing.
  5. ...and you'd never drive to the end of a dead-end to turn around anyway.
There are a small number of U-turns left around the country, which we'll be clearing manually, and we also expect to see new ones popping up every day. We shall talk to HQ about how these can be prevented.

That is all.
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Post by ditchi56
Why do they still pop up?

I've just run a Validator scan and found four new dead-end U-turns, none of which have been edited recently.

Example
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Post by PealRinger
ditchi56 wrote:Why do they still pop up?
I think it's because of a recent drive - although I have to admit I rarely see any GPS points to support this but it often seems there's a big lag before the traces show in WME.

My understanding from the Wiki is that soft turn restrictions (including U-turns) get converted to allowed turns if someone using them.
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Last edited by PealRinger on Wed Jun 25, 2014 12:56 pm, edited 1 time in total.

Post by PealRinger
Timbones wrote:
  1. In the UK, roads are usually too narrow to safely perform a U-turn manuveur.
  2. Places where U-turns are safe to perform are probably mapped as dual-carriageways anyway.
I agree that having telling a user to make a U-turn at a particular place is risky and prone to problems.

However it seems to me that a 'turn around where possible' instruction would be more useful in some circumstances. Most junctions in the UK have space to turn a car whether in a single turn or by reversing round the corner as per the driving test manoeuvre.

I've seen some very tortuous circular routes being calculated when (not very often :oops: ) I've missed a turning. It's not always clear that's what Waze is now trying to get you to do, but it's often far quicker/shorter to pull up at the next junction and turn around.
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Post by Timbones
ditchi56 wrote:I've just run a Validator scan and found four new dead-end U-turns, none of which have been edited recently.
If an editor accidentally or purposely enabled the U-turns, you wouldn't be able to tell because WME doesn't record changes to nodes. If they'd touch other segments nearby, then you might be able to surmise it was them.

There are still the odd few scattered about, but they are usually very sparse.
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Post by venishbede
I've noticed a smattering of u-turns which are flagged by the Validator, but seemingly the road itself does not appear to have a u-turn symbol to disable (i.e. https://www.waze.com/editor/?env=row&lo ... =121902152).

This particular highlighted road is highly unlikely to cause any particular issue, but is this user error on my part with the Validator or other resolution?
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Post by Timbones
U-Turns are gradually sneaking back in, and Waze are working on a more permanent solution.

Also, the last WME update removed the U-turn arrows from the ends of the dead-end segments, which is why you cannot see them.

Ignore them for now, and move on to fixing other issues.

:ugeek:
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Post by venishbede
Ah - thanks for pointing that out.
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