Time based turn restrictions

[WeeeZer14]

With the change from "disallow" to "allow", the phrase "on the side of caution" is out of place and doesn't make sense.

I think that if we have to chose our poison, a safe, conservative, always legal approach is best. It isn't good to have Waze keep telling you to make lefts along a road if they are all disallowed for the morning rush. I think that is worse than telling someone to go a mile down the road and turn there instead of using the little side road you know if better. One is annoying while the other is frustrating.

Until we get time based restrictions, we are stuck between a rock and a hard place.

[therubinator]

This change was noticed in October and Jhfronz responded for the motivation in this thread. It appears there was no resolution as to how to update the wording to recognize the group consensus.

Wow, that turned a little ugly, didn't it.

From earlier in that thread, jhfronz says

Here in the US we have remote-controlled animated signs that can suddenly say "no turns" (when traffic gets weird and the traffic control operations folks want to optimize things), but allow turns the rest of the time.

So I think there's room for improvement. This approach is black-and-white whereas some amount of discretion could be used. jhfronz's example points out a short-term restriction which, in that case, perhaps makes sense. However, if a more nuanced approach were taken say, given certain conditions then it might avoid confusion (and also make Waze more useful, rather than less, in those situations). For instance, what if the recommendation were to allow the turn if the restriction were:

• not during rush hour (defining rush hour being slightly fuzzy, but based on the area and the volume of traffic - assumes the editor knows the area well)
• not more than 4 hours long (for example)
• not cumulatively more than 12 hours of the day
• not a turn on a single-lane road (just spitballing now)

...and then disallow the turn if any (?) of those conditions are met.

Previewing your new post, kentsmith9, I agree on both #1 & #2:

1. Does the group generally agree with the philosophy of the statement that Waze should give the best route and let the user decide if it is legal?

Waze preferably wouldn't direct you into a gaping canyon based on incomplete map information, and shouldn't direct you the wrong way down a one-way street. So why should it direct you into a turn that is illegal 50% of the day and 100% during rush hour?

2. Is the specific wording "to err on the side of caution is to sometimes recommend an illegal turn"?

I agree those words are not necessary and I think the best practice recommendation should allow for editor knowledge of the area as well as some of that fuzzy logic suggested above...

[harling]

There are now two questions in my mind:

1. Does the group generally agree with the philosophy of the statement that Waze should give the best route and let the user decide if it is legal?

2. Is the specific wording "to err on the side of caution is to sometimes recommend an illegal turn"?

I strongly disagree that to give illegal (and most likely unsafe) directions is to "err on the side of caution." Waze should only give directions that are guaranteed to be legal and safe. If a local driver knows a "short-cut" that Waze does not suggest, he can complain until Waze implements time-based restrictions; it's better than complaining that Waze cost him a $50 ticket, or a $5000 hospital bill.

[CBenson]

Until we get time based restrictions, we are stuck between a rock and a hard place.

Yep. I've basically given up on the time based restriction issue. The wiki is just a manifestation of the chaos on the ground. The turn restrictions in downtown DC are in a constant state of flux.

Add to that the fact that there is no way to see who is doing what with turn restriction. Thus, there is no way to initiate the local conversations needed to get everyone on the same page. So it doesn't really matter to me what the page actually says. Currently my practice is to leave time based restrictions in whatever state I find them and add a notation to the map with the actual restrictions.

Being in a rather cynical mood, I'd suggest replacing the entire section with the statement that the ability to add time based turn restriction is coming soon (right after states are added on the world server).

[therubinator]

One further point which may be useful to consider: the whole point of time-based restrictions from the point of view of urban traffic management is to control traffic flow and ease congestion (ideally). That said, from Waze's perspective it should already be rated a less than ideal route (assuming the AI is working properly). Blocking it outright wouldn't be the worst thing and would certainly eliminate the possibility of directing the user into an illegal route.

[CBenson]

1. Does the group generally agree with the philosophy of the statement that Waze should give the best route and let the user decide if it is legal?

Waze preferably wouldn't direct you into a gaping canyon based on incomplete map information, and shouldn't direct you the wrong way down a one-way street. So why should it direct you into a turn that is illegal 50% of the day and 100% during rush hour?

Huh? Waze will route you many many crazy ways based on incomplete map information. This is certainly true with one way streets. If the one way direction changes during the day then waze will route you the wrong way on the one way street.

I don't advocate setting turns as open if they are illegal for 50% of the day and 100% during rush hour. However, the argument, as I see it, for leaving them open (say if they are illegal only during one rush) is that it is much easier to determine what the waze route is taking into account if it is left open. In other words, you can make the determination on your own that waze is routing through an illegal turn and ask for alternative routes. There is no way to look at route that doesn't go through a legal turn and determine whether the route that goes through the turn is actually currently faster. I'm not saying that this reason is stronger than the reasons for restricting the turns. I'm just pointing out that a reason does exist.

[WeeeZer14]

I don't have any good examples of time based restricted turns handy, but a question for those of you who do...

Assume you have a turn which is restricted for only one of the two rush hours. All other times you can make the turn.

Assume you are driving at a non-rush hour time.

What is the impact of NOT taking that turn? Is your route significantly increased?

[CBenson]

One further point which may be useful to consider: the whole point of time-based restrictions from the point of view of urban traffic management is to control traffic flow and ease congestion (ideally). That said, from Waze's perspective it should already be rated a less than ideal route (assuming the AI is working properly). Blocking it outright wouldn't be the worst thing and would certainly eliminate the possibility of directing the user into an illegal route.

But the decision to restrict a turn from the perspective of urban traffic management is to improve the collective traffic flow. Waze should be attempting to provide the best route for a specific individual. There is no particular reason to believe that turn that improves collective flow during restricted times is less than ideal for any particular individual during the time the turn is legal.

[shawndoc]

So I think there's room for improvement. This approach is black-and-white whereas some amount of discretion could be used. jhfronz's example points out a short-term restriction which, in that case, perhaps makes sense. However, if a more nuanced approach were taken say, given certain conditions then it might avoid confusion (and also make Waze more useful, rather than less, in those situations). For instance, what if the recommendation were to allow the turn if the restriction were:

• not during rush hour (defining rush hour being slightly fuzzy, but based on the area and the volume of traffic - assumes the editor knows the area well)
• not more than 4 hours long (for example)
• not cumulatively more than 12 hours of the day
• not a turn on a single-lane road (just spitballing now)

I'm simplify it to the following:
- Disallow the turn if most drivers are likely to encounter the turn while it is restricted

[therubinator]

Huh? Waze will route you many many crazy ways based on incomplete map information.

I did say "preferably"

In other words, you can make the determination on your own that waze is routing through an illegal turn and ask for alternative routes. There is no way to look at route that doesn't go through a legal turn and determine whether the route that goes through the turn is actually currently faster. I'm not saying that this reason is stronger than the reasons for restricting the turns. I'm just pointing out that a reason does exist.

I disagree - I don't think you can always make the determination before it's too late. I have a good example but it's going to take me a moment to dig it up.

But the decision to restrict a turn from the perspective of urban traffic management is to improve the collective traffic flow. Waze should be attempting to provide the best route for a specific individual.

As a pithy ad I saw recently said, "you're not stuck in traffic: you are traffic." The best route might for the individual might not actually be valid (hence, my canyon example). Again, until Waze can actually make the most informed decision possible (i.e. time-base restriction handling), we're kind of hacking now, aren't we?

I'll be honest: my motivation for discussing this is purely because I've been repeatedly directed down bad-advice turns and would really rather be sent down the "next best" route than the "best route" that's wrong/illegal.