Traffic jams appear then disappear - rediculous!!

mu71rd · Occasional Visitor Joined: Jun 29, 2005 Posts: 6

I was on my way up the A1 this morning (unfortunately) and suddenly I was warned about the massive congestion because of the M25 being closed. TomTom started rerouting me, then suddenly, on the next update, all the congestion aroudn that area disappeared, so I put me back onto my original path.

then five minutes later, and once it was too late to turn around, the congestion warnings all re-appeared again, so I had to sit in traffic for 45minutes.

How can the system be so stupid?! Jams don't just disappear in an instant - and why would it then reappear. Has anyone else noticed this behaviour?

HielandLad · Posted: Wed Jul 06, 2005 4:50 pm Post subject:

I noticed it this morning as well in Scotland due to the G8. Each update seemed to toggle between there and not. Must be something wrong with the server or something.

mikealder · Posted: Thu Sep 29, 2005 5:35 pm Post subject:

My first proper run with traffic running today on the XDAIIs - on a 400 mile run, it warned me of a problem at the A1/ M62 junction, which after 15-20 disappeared , it reapeared as I joined a jam that cost me 1,5 hours - jury is out on whether to continue after the trial, need to try it more to get used to it - mike

StevePritchard · Regular Visitor Joined: Aug 15, 2005 Posts: 78

It does do this occasionally, I've noticed - the giveaway is that all congestion goes, apart from obvious "long term" congestion, e.g. roadworks with blocked lanes.

If it looks as though all hell has broken loose and it's Carmageddon, then it clears in an instant, there's a fair chance it's a hiccup on the server.

Cheers,

Steve.

arndale · Occasional Visitor Joined: Aug 24, 2004 Posts: 17

I've also had this on my first outing with Traffic. It told me that the M25 was congested then told me it was OK 10 minutes later. About 2 minutes after I'd joined the back of a huge jam it told me that there was 4 miles of traffic! Aggghhhh.

This was on my trial. If this happens again I certainly wont subscribe!

Dean

NMatthew · Posted: Sat Oct 01, 2005 8:52 am Post subject:

One thing I first noticed last year with TTN3 (and now possibly with TTN5) was that there seems to be an small issue with the way the traffic data is sent from the server and received by Tomtom. As far as I can tell, TTN3/5 does not get told how many incidents there are at the start of the download, nor what has changed. Incidents get sent as a complete list and TTN3 counts them as they arrive. (For users that did not use TTN3 it shows an incrementing count of incidents as the data arrives).

It would appear that if the connection to the traffic server is made OK, but the download is disrupted for any reason TTN just thinks that all is well, but that there are fewer incidents, sometimes even zero. I suspect that long-term roadwork incidents come first which is why they seem to survive problems with disappearing incidents.

I believe that TTN5 behaviour is the same as TTN3 was, but you do not get to see any progress of incident download - which I think is a backward step. I was always reassured by TTN3 when I saw 200 incidents rather than 11 (if you see what I mean).

As to why the download gets disrupted, it could be server problems or a drop of the GPRS connection from the PDA or phone. Tomtom's error detection being non-existent, it's hard to know.

Neil
_________________
Audi TT Coupe Quattro
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StevePritchard · Regular Visitor Joined: Aug 15, 2005 Posts: 78

I think you are probably right in that the traffic data can be disrupted without it being obvious. I'm pretty certain that the long term stuff isn't sent every time - it just has a time-out within TTN which avoids large downloads.

Bascially, as far as I can see the traffic service contacts a website (http://tt1-test.tomtom.com) and get's a response with the traffic data encoded in it (don't bother accessing it with your browser, it doesn't return anything). We all know that websites can suffer the occasional glitch, and I guess even if the data at the back end can cope, it's possible that there are a lot of us trying to get frequent updates during the rush hours...

Cheers,

Steve.

mikealder · Posted: Mon Oct 03, 2005 9:31 pm Post subject:

Second decent run today, and the last time I will post unless I fall out traffic, it saved me a good couple of hours today, I even got the TT alert around 30 min prior to any warning over the RDS equipped radio, very impressed to say the least if it keeps up like this I will be paying for it, unless the free trial gets extended? - Mike

Masked-Marauder · Regular Visitor Joined: Aug 18, 2005 Posts: 89

Well I had is showing a 7 mile tailback at Brampton Hut on Tuesday night. 5 minutes later all 7 miles of traffic was reported as gone, and when I got there about 15 minutes after that it had indeed gone, thats if it had been there in the first place that is!

I have had it flag delays on the M1 and nothing there, The A43 and nothing there and on the A1 and nothing there. The only time it flagged a real delay for me was just after I got stuck in it......

I do drive for living btw, 3.5k miles a week and I had a eight week trial of traffic. so that means it never got it right once in 28,000 miles. Thats my personal experience anyway.

But believe it or not, I am seriously giving the benifit of the doubt and paying for a subscription.

StevePritchard · Regular Visitor Joined: Aug 15, 2005 Posts: 78

My feeling is that it just lags behind reality. So you can find that there is no delay where it reports, and a delay where it doesn't report it yet. I guess this pmeans that when they get it to catch up with reality, then it will be a good service. I started my trial in June, and it's due to end in November - I think I'll probably pay for the service at that point - it does occasionally warn of a real delay. Combined with the gantry signs, I think it could be useful...

Cheers,

Steve.

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