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Re: No through traffic

Mon Sep 01, 2014 7:22 pm

Though it seems even at the far end it'll still do the same thing. Is that a limitation of the live map? Does live map always start you at the middle of the segment anyway? (Judging by the WME travel time script, this is the case.)

Re: No through traffic

Tue Jun 24, 2014 6:24 am

kentsmith9 wrote:The only down side to that technique is that vehicles on the two main side roads that parallel Matteson will not be routed straight across through the middle of the neighborhood, but will be forced to be routed to the main roads on the perimeter.
You forgot about the traffic going "eastbound" on Matteson TO the freeway onramp at the same intersection. All of these unncessary restrictions now destroy Waze's raison d'etre; namely, finding the Smart route, to avoid the complete rush hour gridlock on the three MH streets around this area.
kentsmith9 wrote:There are no other signs on the other roads into that neighborhoods simply because no traffic is coming from those directions
Um, wow.

Since this has now drifted into this thread, and you've opened the side discussion about the right turn here, allow me to present the following:
Sawtelle Matteson west corner.jpg
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which clearly shows the rounded corner, allowing right turns from Sawtelle into Matteson. Were the right discouraged or restricted, the choke area would come out to a squared corner, as it does in many other places in the city, rather than having a gentle curve. Additionally, if traffic were to be restricted from Sawtelle, there would be plentiful signage facing north and south, clearly indicating same, and there would not likely be a Left Turn Arrow light, as there is on N/B Sawtelle.

There are definitely places, like Estrella in Scotts Valley, where a Private Road segment on an otherwise public street is absolutely the correct solution for discouraging Through Traffic -- I've done it many times myself, in other places -- THIS is not one of them.

That said, my feeling is that there should be a brief mention of this usage under Private on the Road Types page, with a link elsewhere for expansion and clarification. I feel that Private Installation is not the correct place for that expansion, due to the extra confusion juxtaposing Private/Public already causes, so I agree with Kent that a new page, or, possibly another location in the Wiki (not coming to mind at the moment) would be a better place.

Re: No through traffic

Tue Jun 24, 2014 8:05 pm

driving79 wrote:For the 2nd example, I would use the private in, street out that is used for private installation
On the second one I originally considered the Private in, Street out, but that restricts movement from Sawtelle to Matteson. As shown above, there is clearly an allowed right turn from "southbound" Sawtelle, and this left turn arrow on "northbound" Sawtelle
Sawtelle Matteson left turn arrow.jpg
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clearly shows that traffic is allowed there. Along with the lack of any north- or south- bound signage it's pretty obvious the only thing intended to be restricted here is the freeway offramp traffic. For this, a TR from the offramp serves essentially the same purpose without limiting the Sawtelle traffic.

Re: No through traffic

Tue Jun 24, 2014 10:56 pm

driving79 wrote:So what if I'm coming off the ramp and going straight because I live there? Wouldn't a TR stop that? I don't think they really want tons of people turning right from Sawtelle that don't live in there either, I get it's not clearly posted from that direction. If you only do the TR from the ramp, then waze may do funky routes from the ramp to get them to turn right onto Sawtelle, uturn using other streets nearby and then turn right onto it (because it would still be faster). Not ideal.

Basically, what CBenson said about the one Private segment doing the same thing as a TR. It's pretty clear to those of us who live here and have driven that area, that the amount of traffic turning from Sawtelle to Matteson was never a problem. It's the HUGE number of people getting off the freeway there, and looking for a way to avoid going to Venice and Washington Place to go westward. This freeway, the 405, is literally known as the busiest in the country. (and if you don't believe Wikipedia, just type "busiest freeway in US" into any search engine.)

It's not just "not clearly posted" it's just NOT posted. If traffic were going to be restricted from Sawtelle, the City would definitely have let us know about it.

This offramp has been set exactly as it is right now for about a year, and this is the first "complaint" I've seen. And I'd be at least somewhat surprised if the person who asked for the unlock actually lives in that city block (I've asked, haven't heard back yet). The very few Wazers who might live in that city block can learn to ignore the instruction, and probably already have, since they know about the "No Thru Traffic" sign.

Believe me, funky routes like that are never going to be faster there unless it's the wee hours of the AM. Venice, Sawtelle and Washington Place are all very busy roads during the day. Again, first complaint I've seen in a year, and the unlock request appears to have been in error.

vectorspace wrote:The sign says NO THROUGH TRAFFIC, so it doesn't matter from which direction the traffic is coming. The sign is still there. So, I think we could dismiss the idea that only traffic from the off-ramp is restricted (because of the extended curb area). Does anyone disagree?
YES. If the through traffic were meant to be restricted from Sawtelle there WOULD be signage posted, facing north and south, not just one sign you can't actually read until you're in the middle of the turn. Culver City is not shy about that. As I stated previously in this thread, the curb would be squared, not rounded, and there would not be a left turn signal. It's just not the intention. (edit note: I'd originally posted LA, then changed it to Culver City, then back to LA: this is right at the border of Culver City. 2nd edit: Finally checked a trusted map, had it backward, this is CC)

Plus, making a whole city block Private restricts a lot of crucial Waze routing. Where's the Smart in that?

Bottom line in this case, trying to provide for the very few people who might need to be routed into that area from that offramp does not outweigh the harm imposed on at least tens, if not hundreds of trips through that area each day. I guarantee if that city block is all set to Private, there will be at least an order of magnitude more Map Issues to deal with.
Last edited by tonestertm on Wed Jun 25, 2014 12:37 am, edited 1 time in total.

Re: No through traffic

Tue Jun 24, 2014 4:47 am

This is an interesting topic...

I did a little research about this and it seems that these signs are not always enforceable, yet there is likely wide variation in different cities and jurisdictions. Some argue that it is fundamentally illegal to post such signs because the roads they "protect" are public. In many cases they seem to try to protect a residential area as a shortcut from rush-hour traffic or the like. In any case, once a cop writes a ticket, the pain starts one way or another even if you get out of the fine.

I know that in Albuquerque they solved this issue with more expensive means, by putting in small traffic circles in or barriers to through traffic... only right turns allowed due to blocked straight through access.

I am certainly for using private roads or expanding the Private Installation page with a "No Through Traffic" section but think that a deeper explanation of what you're trying to accomplish might be needed. Some of these "No Through Traffic" areas may be more one-way prohibited flow of through traffic. Putting in too many private roads might hinder traffic that is legal. If it is a single street, then it is easy -- just make it a private road. If it is a whole residential area, there might be side effects. Some of these may also better handled by time-controlled turn restrictions.

Do we have a small set of use cases that could be conveyed?

Re: No through traffic

Tue Jun 24, 2014 10:30 pm

Who would have thought "simple" traffic routing would be so complicated?

I think the turn restriction from the off-ramp discussion is likely one of the most complicated instances of this topic we have and that I can think of. Trying to restrict routing to an internal destination (private area) from only one direction but not others?

Perhaps we make this too complicated. The sign says NO THROUGH TRAFFIC, so it doesn't matter from which direction the traffic is coming. The sign is still there. So, I think we could dismiss the idea that only traffic from the off-ramp is restricted (because of the extended curb area). Does anyone disagree?

If we step back from this, I think there are some simple cases that can be made on this topic in the wiki. For instance, if a single road segment is for local-only traffic and there are signs on both sides of that road, then the solution is easy -- just make that road segment "private."

As Driving79 points out, making a whole neighborhood private causes some routing issues out of the neighborhood... I didn't even know that and now smile because that means the Private Installations page should be updated with this knowledge and bias against that practice should be added. I will discuss with her and Eric.

I think Qualete and Driving79's comments on using closely spaced two-way segments, one being private, is also a really good solution to cause the penalty in one direction. As long as the no-through-area is small, this solution should work to discourage no through traffic from entering only in that direction. As the no-through-area becomes larger, then it starts looking like a private installation and all entries to that neighborhood would have to be treated that way.

I have had experience with turn restrictions serving this very function because the no-through traffic issues are usually related to morning or evening traffic or in a couple cases I saw, with the arrival or dismissal times of students at a school. In these cases the turn restrictions are usually labeled and we can just treat them directly in that way.

Does anyone have other examples of no through traffic area types that would not be covered by these?

Re: No through traffic

Wed Jun 25, 2014 12:42 am

Fredo-p wrote:
vectorspace wrote:The sign says NO THROUGH TRAFFIC, so it doesn't matter from which direction the traffic is coming. The sign is still there. So, I think we could dismiss the idea that only traffic from the off-ramp is restricted (because of the extended curb area). Does anyone disagree?


Well, what I was trying to point out in the last post I had with the screenshot was that the sign is in the direction of the off-ramp. If we go by how sings are displayed, we know that the direction of the sign is were the intended instruction is meant for. Since there is no other "No thru traffic" sings facing the other directions, it's safe to assume that it's meant for the off-ramp traffic so they don't go packing through the narrow opening. ...


tonestertm wrote: ... YES. If the through traffic were meant to be restricted from Sawtelle there WOULD be signage posted, facing north and south, not just one sign you can't actually read until you're in the middle of the turn.


Oh, OK, my misunderstanding. I had the impression the sign was faced to read as you were going into the street... That makes sense.

Re: No through traffic

Wed Jun 25, 2014 12:52 am

Fredo-p wrote:I tried to explain this before, but I wasn't going to type it all out on my phone. Now that I'm on my laptop, this is something that I would like to know if it can be done.

Is it possible to have the navigation and penalty algorithm include codes that checks the destination address location for road types?

What I mean by this is, for example, using this ramp discussion, a user wants to go to destination A. Destination A is on the other side of the community. Having the road segment set to private would penalize it and cause Waze to an alternate route. ...


I believe I understand what you're saying, but my quick answers are (a) that it doesn't matter, and (b) that Waze programmers can do just about whatever they want with the algorithm -- we have ability to influence but only if it has a significant impact.

I don't think it matters because Waze will consider a number of routes (in some way optimal for paths and computational time). Typically this is the A* algorithm, described here. All of those paths will have penalties associated with the entire path including the destination limitations that we're talking about here. To adjust the algorithm in the way you describe is probably non-optimal for the general case.

Re: No through traffic

Wed Jun 25, 2014 1:00 am

Fredo-p wrote:After checking Google Street View, I have noticed that nearly every road south of this location is sporting the "Private Road" sings. So how would this be addressed?


Good observational work... I wonder what these various examples you have shown are all about. Truly private roads are owned by the residents or a neighborhood association of some type, and usually maintained by those people. These roads look like they are public. Anyone can put up a sign though to try to keep people out. I wonder what is really going on with these?

The signs you show and that I could see on street view look like they were posted by residents, not a municipal authority.

If they are really private property, then I would say we could go with the Private Installation page guidance and those updates which we're trying to develop in this discussion.

If someone just posted signs, then I would not bother to adjust the map.

I guess one could further research the topic to see exactly who owns these roads.

Re: No through traffic

Thu Jun 26, 2014 5:08 pm

Exploring another topic, I wonder if txemt and Driving79 can expand on their observations of how neighborhoods marked with Private Roads do not route well. This would help us understand how to address this in parallel with understanding the issue. We might also update the Private Installations page.
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