GO 740 LIVE traffic service?

[NorFowl]

Uh, ok, I'll delete my link.

A good opportunity to paticipate, I hope, in this experimental venture between two different sites.

Sorry, Didn't mean to step on toes... didn't see your link in this forum, and since it's coming up so soon I brought it over here because this group is really hot on this topic. (Note that I retained your original links).

 

[dhn]

Not at all, I appreciate your doing it. I just type tooooo slooooooow!

 

[gatorguy]

It took two of us three days to get a handle on it. And both of us were already very familiar with traffic systems and what is available. But once you do, you realize how little effect daily traffic has on a computed route. As we go along, things should begin to make sense.

 

[dhn]

Interview scheduled for this afternoon with TomTom traffic rep (Tuesday, May 5th) at 1:30 pm Eastern.

 

[NorFowl]

It took two of us three days to get a handle on it.

GatorMan,
To what are you referring to here? I've been looking for the results of your driving tests, is this it? Where're they posted, eh?
Inquiring minds want to know!

 

[dhn]

Gator and the admin, Tim, at gpsreview.net did 3 days of rigorous, and I mean rigorous testing of traffic on the 740. The results will be incorporated in a review of the 740 that Tim will prepare shortly. When he does, I'll provide a link here.

 

[gatorguy]

Yeah, DHN saw the posts flying from early morning till late at night.

Really didn't answer all our questions till Sunday. But the review will be all Tim's work. That's his job.

 

[mvl]

From the brit forum - LIVE traffic appears to work on Operate my GO with app 8.350. Anyone confirm if US LIVE works too?

 

[Michael Quinlan]

A limited experiment...

On my way home this afternoon, I used my 740 to guide me home, and purposely drove slowly (30-35 MPH) on the normally free-flowing highway near my house. After getting in the house 5 minutes later, I opened a web browser to look at the following sites for traffic info:

maps.google.com
maps.yahoo.com
traffic.poly9.com​

Both maps.google.com and traffic.poly9..com showed slow (yellow) flow on the roadway I had just driven slowly on. maps.yahoo.com did not. About 15 minutes later I checked all three sites again, and the results were the same. At this time I also checked LIVE traffic on my 740 - there was no indication of traffic on the same roadway. My own experience is that this is area is never congested, so LIVE should have shown this as a variation from IQR data.

 

[tflight]

My own experience is that this is area is never congested, so LIVE should have shown this as a variation from IQR data.

If I understand what you were doing, I'm not sure I'd agree. One vehicle isn't be enough of a confirmation that the traffic is slow. They require multiple probes before declaring an anomaly from their predicted patterns.

Also you can't assume you were the only probe vehicle on that stretch of road at that time. 740 owners are a drop in the bucket compared to the total number of probes being used. So if another probe passed you on the road then your probe data could have been demoted as unlike the other data they were getting.

Even if they did register one vehicle as enough data to declare a traffic slow-down, you didn't check it until five minutes after you got home and then 15 minutes later (a total of 20 minutes after you got home) so the information could have (should have even) been discarded as being too stale to use as real-time data.

For that type of test to work you would need multiple vehicles as well as someone checking sites as you were driving or within just a couple minutes of you driving.

 

[Michael Quinlan]

I realize there wasn't enough information to draw a conclusion, but it was interesting for me to try. I can confirm however that I was the only one traveling in that direction on that road at that time. What I don't know is what each site displayed before I travelled that road. There may have been someone a few minutes behind me, but it's one lane in each direction, so other traffic is readily apparent.

I do find it interesting though that traffic.poly9.com claims to get their traffic data from Yahoo, but the traffic data they display matches Google, not Yahoo.

Since getting my 740, I have observed several occurrences of slow (red) traffic on that road displayed on both Google and Poly9. I can also see the road from my house, and know for a fact that there was no backup at that time, or at any time prior time where the data might still be considered valid. With rare exceptions, congestion on this stretch of road is unheard of, so the recurring display of slow traffic on these sites must be either predictive (erroneous), or live data from a small number of vehicles travelling slowly for some reason other than traffic. In this area, the most likely reason for driving slower than desired is being stuck behind a tractor or construction vehicle on the road. With one lane in each direction, and somewhat limited visibility, passing is not allowed.

I'll be travelling to a more congested area tomorrow, and will be able to compare PLUS and LIVE side-by-side. Given the filtering used by the LIVE service, I expect the traffic displays to be different, but the resulting routes should be the same.