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Re: Does Waze consider smaller roads into it's routing?

Posted: Thu Dec 06, 2012 3:33 am
by mirarkitty
WeeeZer14 wrote:
RodNav wrote:if there is sufficient historical speed data, why even consider the road type?
Scalability is why. If I am trying to find a route from NYC to LA across all of the US, it would take infinite resources to check every possible route. So we reduce the calculations required and only examine a subset of road types.
This is not true. You can start with the long roads (Freeway). Then do checks on the closer roads if there's a possibility for it to be faster. As soon as it's not faster, you can skip that entire path.

Besides, I'm sure my phone is happy to lend you a lot of computrons if you lack them on the server. I'm 100% sure the map of the nearest roads in a 1000km radius fits on my phone.

Re: Does Waze consider smaller roads into it's routing?

Posted: Thu Dec 06, 2012 8:32 am
by mirarkitty
AlanOfTheBerg wrote:
Mirarkitty wrote:Really? Well, that explains a lot...
Why not use all the roads all the time?
Now, how Waze (re)considers street type when extreme slowdowns/accidents occur is another topic perhaps, but that's just me musing.
Well, I thought that was exactly the topic - that it only picks Freeways anyway, even though it takes 6 hours longer than the Minor next to it (2 vs 8 hours)?

It would make much more sense that it only used roads going faster than say 50km/h at all times the last month when searching the roadgrid than going on the road type.

Re: Does Waze consider smaller roads into it's routing?

Posted: Thu Dec 06, 2012 8:34 am
by mirarkitty
For myself, I've seen this: When driving to work from home, it avoids a service road shortcut (~1 minute). When driving to work from the nearby post office, it uses that shortcut. When driving home from work it's using that shortcut...

(I don't think I can recreate it: the grid has changed now.)

Re: Does Waze consider smaller roads into it's routing?

Posted: Thu Dec 06, 2012 11:31 am
by mirarkitty
kotatsu wrote:This is very much still a problem unfortunately.
...
So when the traffic is bad, I'm still using Co-Pilot, as it simply knows more routes. I also find that Co-Pilot is much more realistic with its estimated time of arrival when the traffic is bad.
I completely agree that this is a huge problem. If you can't trust Waze to give you a decent route, then there's no point in using it.

I can only suggest that you take the correct route as suggested by Co-Pilot but let waze run at the same time, to maybe, possibly, learn something. And try to fix or at least report map problems.

On the other hand, it can't be as simple as ignoring road types, I realized. When I were driving Krems-Graz in Austria (a trip for a few hours), it happily suggested an overland road as a shortcut - can't have been more than a Minor. Maybe it's gotten more stupid since August?

Re: Does Waze consider smaller roads into it's routing?

Posted: Fri Dec 07, 2012 8:29 am
by mirarkitty
bgodette wrote:Yes lets completely ignore the rest of the thread after that list and go on a trip of hyperbole. That list has been proved to be in disagreement with how routing actually works with a well edited map with sufficient user density.
If you read all the posts, you might also note that I personally also had evidence that it's not that simple:
Mirarkitty wrote:On the other hand, it can't be as simple as ignoring road types, I realized. When I were driving Krems-Graz in Austria (a trip for a few hours), it happily suggested an overland road as a shortcut - can't have been more than a Minor.
But then again, maybe you were serious. I think you mean tangent though?

I find it a little disappointing that there seems to be so many very sure statements about how Waze works, that doesn't seem to come from any developer, and are rather naïve ideas on how these kind of systems work - they don't make complete sense, and are debated. It would be nice if the devs could pipe in and explain how it works rather than have it debated here.

Re: Does Waze consider smaller roads into it's routing?

Posted: Sat Dec 08, 2012 10:49 am
by mirarkitty
xteejx wrote:Also, the way the algorithms work will never be divulged by Waze. It's their secret sauce, so we as editors and users can only speculate on how it works.
Why is that? I thought Waze' business idea was to sell the data the users generate.

There will be more users if the maps and routes are better. They will be if the editors and users know how to work with Waze.

How to make routes / path-optimizations is one of the oldest and most basic problems in computing algorithms. I doubt they have anything very clever.

Re: Does Waze consider smaller roads into it's routing?

Posted: Fri Dec 07, 2012 1:27 pm
by OldGnome
I live in the Tampa, FL area and drive a couple hundred miles each week in the local area and across the state. Waze has always been able to show me an alternate route when I have asked for one.

Re: Does Waze consider smaller roads into it's routing?

Posted: Mon Dec 03, 2012 9:42 pm
by PhantomSoul
I don't agree with using streets or other lower-grade roads for long trips at all. Fact of the matter is that 99% of the time it's always better to sit out regular congestion on the freeway or other large road than it is to try and detour it on surface streets.

I've tried this many times myself, largely because I easily get annoyed if I have to drive on any road at speeds significantly lower than the speed limit, and I've found unless there is some kind of acute incident - like an accident - that closes the entire road - in which case there would be a forced detour anyway - trying to detour highway traffic on surface roads has hardly ever gotten me to my destination faster, and in most cases it actually got me there later. Even for things like accidents, the nearby surface roads are going to be totally gridlocked with like half the other cars from the highway trying to do the same thing - and surface roads are just plain not designed to handle that kind of traffic.

The only way to really effectively be able to expect to cross urban areas at highway speed limits is during off-peak times, when traffic is light. Perhaps a more useful feature might be a delay estimate, in say minutes, of the traffic ahead on the route. A lot of the state highway signs that tell you how long it takes to go a certain distance are very useful in this regard and it might be nice to have a more-scaleable version of it in the navigation

Re: Does Waze consider smaller roads into it's routing?

Posted: Mon Jul 16, 2012 5:31 pm
by RallyChris
The routing code is a "secret formula". Which makes sense, since this not an open source project, but a business.

What we have been told about the behind the scenes working, is that waze will put a higher preference on higher and higher types of roads based on the distance of the route. (IE: as you go up in distance, the more and more it will prefer to use freeways only)

Waze makes it sound like they will not even consider some types of roads based on the distance, but real world examples make this seem to be incorrect.

More like (and my opinion) is that the longer the route, the higher the penalties waze puts on using a lower type of road, and maybe the more likely waze stop trying to make an alternative work.

Also putting a different spin on it, is if the traffic was discovered after the initial route was created. I've seen little data from waze on how this is handled. When does it start looking for alternatives? Does it just try to find how to get around the traffic or does it just recalc from where the traffic starts?

Re: Does Waze consider smaller roads into it's routing?

Posted: Mon Jul 16, 2012 10:49 pm
by RallyChris
Antmannz wrote:I have a feeling junction points also create quite a penalty when calculating routes.

I've seen where a misplaced additional junction point on a primary road caused Waze to route around back streets to avoid it (reducing the total number of junction points traversed).

In theory toll roads, freeways and motorways should have less junction points than standard streets (especially over a distance), thereby giving them quite a precedence when being chosen.
When they first started waze, we were told that a junction adds a 5 second penalty.

The last we saw, was that junction where there were no options don't have a penalty.

Again, this is black box and what they leak. And sometimes I think they misspeak themselves. So take the above with a grain of salt.