foxitrot wrote:

Autourdupc wrote:I was driving at 131 km/h, and Waze said that the average speed was 58 km/h.

What about the wazer in front of you? May have caused it as well...

...then the jam would have disappeared after driving 1-2 km into the segment. Did it?

On a stretch of road the speedlimit was adjusted from 70kmh to 50kmh, some 6 months ago. Since then every wazer going over that stretch with 50kmh causes trafficjams - of 50kmh (yellow). Even though there has not been a single Wazer going at 70kmh over a period of 6 months - the maximum speed was never adjusted.

I see this a lot lately, often on the same roads, so it might be network related indeed,

This afternoon, I hit some medium traffic. The strange thing was, that two segments in front of me also turned yellow. AFAIK, there were no other wazers arround, and traffic was flowing freely at those segments (selected in the permalink).

https://world.waze.com/editor/?zoom=4&l ... ,161092588

http://img.tapatalk.com/d/12/09/22/muqubymu.jpg

I am not understanding the first post. 'Ghost' traffic jam meaning what?

False, traffic jam? Ie, you are not travelling with traffic (stopped at Drive Thru, Gas station, etc), and your Waze session creates a false jam on a nearby segment? Is this the information that is being requested?

Ghost traffic jam would be as AlanOfTheBerg describes, a jam that appears and there is no Wazer (including you) in the vicinity. No Wazer = Ghost.

johnarbor wrote:I don't presume to know exactly how waze makes the determination, but would it not make sense, that waze could tell the difference if a car came to a stop, moved 5 feet, stopped, moved 5 feet, stoped vs car coming to a complete stop and sitting there for 5,10,15 minutes whatever, and then continuing on it's way?

Although isn't this the exact driving behavior if you are at a drive thru window at a fast food restaurant?

nnote wrote:https://www.waze.com/editor/?zoom=7&lat ... TTTTTTTTFT

At this drive through, waze used to keep me snapped to the nearest road to the west and cause 'ghost traffic jams'. Ever since I put a parking lot road in the drive through and left it disconnected from the nearest roads, I've never had the problem since. When I leave the road and start through the drive through, waze knows I'm there and since it's parking lot road it doesn't say there's a traffic jam in the drive through either. I've done this in drive through's all around my area and it cut down on auto generated map errors and false traffic jams substantially. So, basically I've solved this issue in my area.

What happens when you are on one of these parking lots roads and start a new route?

jenncard wrote:Yesterday I spent 10 minutes at a gas station (no parking lot road, so I was snapped to the adjacent minor hwy).
NO jam created!

With our understanding of the 'lowest 50 meters' traffic filter (may or may not still be relevant), if your gas station adventure didn't have you snapped to the adjacent road and travelling more than 50 meters, your speed data should have been disregarded - no jam created.

Although who knows if Waze has already made change(s) to the traffic algorithm or is just trying to get some examples so that they can make a future change.

This week I have noticed that is seems that legitimate traffic jams on the freeways are now not being generated in some cases - even when placing a manual traffic jam report that is supposed to make the automated jams 'more sensitive / double weight'.

So if Waze has already made some changes to help avoid false jams from being created, it also appears that they may be now affecting legitimate jams that should be created.

jasonh300 wrote:If this was the case, you'd never get a jam anywhere in a dense downtown type area where the blocks are only 100 m. Or maybe my idea of 100m is distorted.

How big is a city block?

100 meters is about average.

Yep, that's part of the issue with this type of filter. Valid traffic information is filtered out to try to deal with Wazers who are running the application when they are not driving with the flow of traffic.

I don't know if you ever noticed, but nearly everytime I run into a traffic jam on a freeway, the speed that Waze has posted seems to be a bit higher than the speed that the traffic is actually moving. Very difficult to eyeball it though. Could be that the 50 meters of data that is discarded is falsely inflating the traffic speed in every segment.

Think about base mapped segments that are loaded with extra, invalid junctions. Every segment between junctions could be discarding valid speed/traffic data.

Disclaimer - The actual algorithms that Waze is using have not been fully disclosed by Waze and/or may have changed.

http://en.wikipedia.org/wiki/City_block

Yes, Waze needs to focus on the automated jams and get everything fixed. We should not have to press anything to affect traffic reporting. In fact, a good argument is that the manual traffic report function could be removed if the automated jam system is further optimized.

As posted many times in other threads, limitations/problems with the current system:

* Jams are not filtered well enough. One Wazer not travelling with the speed of traffic should not be able to create/clear/affect a jam. Either a Wazer who is stopped on the side of the road, a Wazer on a train, a Wazer attempting to make Waze work as a pedestrian, a Wazer on a motorcycle blowing by traffic, or a Wazer in a car pool lane that is snapped to the freeway clearing jams on the freeway.

* The current filtering system is likely discarding valid traffic. (slowest 50 meters of traffic being disregarded for each segment - if still a filter that is in use)

* As well as the recently reported issues with jams - routing not affected by very slow jams or very slow average segment speeds, ETA not correct, alternative routes ignoring traffic, traffic showing correctly but then you set a new route or look at alternatives and the traffic is ignored.

* The traffic event preview screen when setting a route or looking at alternative routes needs to be fixed. Often it doesn't show the correct data.

Basically Waze needs to consider all traffic but also needs a better way to filter out invalid data.

So since we still have no reply from Waze - we still don't know what they are looking for in regards to this thread.