Tmc Dynamic Route Guidance

[Roger Bill]

Hi all

I'm still wondering about the choice between a used IS250 SE and a new SEI with the navigation system. The key difference is that the SEI doesn't include the Traffic Message Channel system which provides dynamic route guidance capabilities. I was wondering if any of you with the full multimedia system could tell me what information is displayed when a traffic problem is reported on the planned route.

Many thanks, Roger

[Parthiban]

Hi all

I'm still wondering about the choice between a used IS250 SE and a new SEI with the navigation system. The key difference is that the SEI doesn't include the Traffic Message Channel system which provides dynamic route guidance capabilities. I was wondering if any of you with the full multimedia system could tell me what information is displayed when a traffic problem is reported on the planned route.

Many thanks, Roger

Really? That's a bizarre feature to remove, especially as it's now standard on Toyota nav systems as well..........

Our Prius has it and I think it's great, pops up with a warning and asks if you want to reroute - actually used it the other day when the A12 had been closed due to an accident, it warned us and routed around it with no hassle

[aido]

Is TMC fully rolled out within the UK now then? If so may need to pick up the TMC adaptor for my TomTom off eBay :D

[Tango]

Is TMC fully rolled out within the UK now then? If so may need to pick up the TMC adaptor for my TomTom off eBay :D

Mine gives me traffic information e.g. lane closed, accident, traffic congestion, slow traffic etc. If there's a potential delay it gives me option to reroute but I'm never too sure if the info is current enough as on the occasion I've chosen not to reroute the cause of the congestion was gone and traffic was moving fairly freely, so possibly the reroute would have lost me time. What is the delay on the TMC system, anyone know?

[Parthiban]

What is the delay on the TMC system, anyone know?

Not really sure, only thing I can use to relate is once on a journey, 5 mins in after setting the route, it rerouted due to traffic - but about 5 mins before we got to the area with the trouble (about 30mins later) it swapped back to the original route as it had cleared.

I'm inclined to say roughly 30mins, but I have no idea :)

[Tango]

I'm inclined to say roughly 30mins, but I have no idea :)

Think I'll answer my own question :winky:

In many countries the source of information is the same for both TMC and traditional radio services. In principle, the information should therefore be the same. However:

• News readers on traditional radio get a fixed slot every hour or half hour, and have to squeeze all messages into a few minutes. Normal traffic announcements can therefore only include a small proportion of all current messages in their limited broadcast capacity.
  
• TMC can support up to 300 messages per hour, delivered as soon as they are created. This lets TMC services broadcast more information, such as road works, and TMC receivers can filter messages relevant to a specific local area or for the current journey.
  
• Some TMC service providers offer added-value information about traffic conditions using dedicated information sources.
  
• TMC messages can be interpreted by your navigation system, where spoken announcements cannot. This means you can usually see on a map display the severity of congestion and in many cases the receiver can work out the quickest route to your destination.
  

Not really answered as it states it CAN support up to 300 messages per hour, but it sounds like it should therefore be more current (and more relevant to the area you're in) than the radio TP's. Perhaps in future I ought to have more faith in what my system is telling me

[Rillo]

I love it. Has really saved me time on a number of occasions. I find that the delay from a problem to being notified is about 30 minutes - so any accident in last 5 minutes will not crop up.

However, my favourite is the umbrella sign and notification of "adverse weather conditions ahead"

Definitely worth having IMHO

[Roger Bill]

Hi all

Many thanks for all the replies. This is really useful information which certainly suggests I should opt for the alternative of trying to find a good used IS250 SE or SEL rather than buying a new SEI.

[GaryC]

Hi all

Many thanks for all the replies. This is really useful information which certainly suggests I should opt for the alternative of trying to find a good used IS250 SE or SEL rather than buying a new SEI.

I had sat nav (COMAND) in my Mercedes C270 CDI and the TMC was pants. The system in my IS250 is light years ahead.

Ok I know it uses the same system but the one I have in my IS250 is nearly always accurate and up to date.

It even shows warning signs for high winds on bridges. It's great as I have my nav display on split screen and the right hand screen is a generally summary of the area and I can see where all the traffic problems are.

[lexulator]

I found it to be much better and more useful than I expected. Although it's not perfectly up-to-date, I have found it to be really accurate on a couple of occasions. It warned me of stationary traffic on the motorway and I chose to ignore, later it said there was staionary traffic coming up in half a mile and I thought 'well I can't see any it must be out of date' then I went round a gentle bend on the motorway and sure enough, half a mile ahead was stationary traffic.

I think it's pretty good. Some of the diversions it takes you on are a bit surprising though - you have to keep the faith once you're committed!

[DJP]

I found it to be much better and more useful than I expected. Although it's not perfectly up-to-date, I have found it to be really accurate on a couple of occasions. It warned me of stationary traffic on the motorway and I chose to ignore, later it said there was staionary traffic coming up in half a mile and I thought 'well I can't see any it must be out of date' then I went round a gentle bend on the motorway and sure enough, half a mile ahead was stationary traffic.

I think it's pretty good. Some of the diversions it takes you on are a bit surprising though - you have to keep the faith once you're committed!

I have the TMC icon on the sat nav screen and occasionally see congested traffic showing but never anything else - definitely no umbrellas! Am I right in assuming that once the TMC is on all this functionality happens automatically, or is there something in the settings I need to be aware of?

[Scarlet Pimpernell]

You do have to switch it on, but you'll find it probably already is. IIRC, you can say "TMC On" with the voice commands...???

Anyway, thought I'd add to this discussion...

I was never 100% with the TMC on the Lexus. I chose to ignore it and more often than not found there were very short delays if any, and quite often there were NO delays...or back it up with AA Roadwatch...

Once or twice I followed it - it took me off the A road or motorway, and by the time I had got to the roundabout/down the slip road it was re-routing me back on to the same Road so I lost all confidence. This incidentally was after the 2nd whole unit (even screen included) was installed.

The BMW TMC appears to be better because it shows you, by small markers, how bad the traffic is (the closer they are the more of a standstill there is) and you can decide to ignore it - but it's only as good as the information sent via Classic FM and how the Car's Nav is programmed to deal with it.

The best one though is the one on my back up Satnav - the Garmin. Always re-routes logically and seem up to do date.

Personally, I would never again buy a new car and specify the Nav - the aftermarket ones are 10% of the cost, and offer heaps more functionality (albeit without a Gyro (electronic compass) and Speed pulse (from the wheels) sensors). The standard sound system on an IS is actually quite good (on the Beemer it's lousy) - though the camera, Bluetooth and MLS are very good, and worth the £2700 or so I paid on top of the IS list price alone...so as a 2nd hand car, I would say buy one with it - you only pay £1000 or so more, and you get all that functionality....

[scott]

I like the TMC, as others have said it does provide lots of useful info and it is up to the driver whether to act upon it. I had one recently that showed me that a set of upcoming traffic lights were out of order - and they were!