Traffic Avoidance

[sparrow2]

I have had my IQ3 for over five years now and I cannot say I am very impressed by the traffic avoidance function built into the TNS510 navigation system. The way it works is that it occasionally pops up a prompt with words something like "Do you want to avoid traffic YES NO". I always press YES and it sends me on a detour. Today I went up to London with my wife and a friend. We noticed the Hammersmith flyover was closed in the opposite direction as we crossed it. My wife said to me "We had better not come back that way". I replied "Do not worry, the traffic avoidance system will sort this out for us if it is still closed when we come back". In the afternoon it sent us back slap bang into the closed Hammersmith flyover! We were stuck there for four hours as three lanes filtered into one. I suspect we could have taken a huge hook to totally avoid the flyover and still got back much more quickly than we did. Why did the IQ not figure this out? I have just checked on the AA website and it gave me detailed information about the Hammersmith flyover closure. I want to go to London again tomorrow and I can see the flyover is closed coming back again. I shall set my own exclusion zone around the area (a feature I have used before with the TNS510) and see how it gets on then.

[tarquin]

Hi

The traffic data is carried by Classic FM and the Tns510 as with most satnav's that are incorporated with a radio tuner use the data stream from the RDS signal thats sent along with the FM broadcast. RDS is the data that you commonly use that displays the Stations name. This doesnt mean you have to be listening to classic FM to get the data. There is a decoder that monitors that stream and feeds the data into the satnav part of the Tns510. Some times if the classic Fm's signal is low the first thing to go is the RDS sub carrier, If the radio part of the Tns510 can not receive classic FM it does not get the information to give traffic update for the maps. Or simply classic FM is not supplying the info for the Hamersmith flyover. This can be because the traffic service is for updates not for ongoing works. I think it is assumed as its been going on for some time it becomes local knowledge. The RDS data is very small in capacity so can not handle continuious allerts. If you were using TomTom instead and paid the subscription service, TomTom send out traffic info via the cellular network. Again this has problems in poor coverage area's

David

[redmini963]

I tend to press No, the other day was going into central London told me to re route extra 25 miles I pressed not and there was no problems or delays.

[sparrow2]

Thank you for the replies particularly the very thorough explanation from David. I will not rely on traffic avoidance so much in the future. Today as I went in to London I saw that, as stated on the AA web site, the Hammersmith flyover was closed coming back and there was a huge queue. Before setting off back I used a telephone number stored in my mobile that I used to often use before I got the IQ to check on traffic to check on the A315, a road parallel to the A4 and which would join up with it after the Hammersmith flyover. It quoted just ten minutes of delays. I followed that road coming back ignoring the sat-nav's instructions to turn left onto the A4 and indeed there were just 10 minutes of delays. I got back home with little problem. Yesterday I was the worst husband in the world with my wife but today I am in her good books again!