Garmin C510d - Poor routing

[AdeJ]

I posted this in the HGV/ Motorhome without success, Just wandered if anyone here could help.

Hi Everyone,
Any help appreciated.

Bought a C510D over Xmas from Halfods to use mainly in our motorhome for UK and a couple of Eurpeon trips planned for the summer. Seemed a great offer at £199 and seeing it reccomended in a Motorhome mag last year took the plunge and invested.
Inital tests in my car proved the unit operating fine, uploaded a POI data base, Speed cameras and purchased the low bridge database from lowbridges.com

Now all set and ready to go I started playing with some routes from my home and I have soon get really dissapointed with the units route choice!!

I have selected the vehicle as a Bus and a Truck, asked it to avoid Uturns and more importantly Unpaved roads (due to the motorhome size). I have selected the fastest route not the shortest and it still insists on routing me down very narrow unpaved roads that I don't use even in the car. There are proper paved main roads (that I use daily) with almost no increase in route length or time.
I am now really concerned that this unit is going to be any use to me at all and that I am going to be fighting down country lanes in a 24 ft motorhome!!
Am I doing something wrong? Or have I bought the wrong Satnav??

Yours,
Ade (puzzled)

[swing]

Best thing to do is to continue to use it every day and see if it gets better. The unit learns your average speed for certain road types, which will influence (to some degree) it's choice of routes.

It is also possible that simply where you live the navigation data is not the best, and the unit cannot tell the difference between the two roads in terms of quality, and hence it has no data on which to decide which road is best.

Also try slightly longer journeys away from home, and see if it continues to suffer.

[inspiredron]

My experience with a 510D in France last June was exactly the same. Occasionally it would route me off the main road down a single track lane which was, presumably, half a kilometre shorter. The impression is that the data contained in the maps is extremely limited, probably confined solely to speed limit. With no appareant difference between a main road and a single track lane in terms of speed information the algorithm will clearly choose the shorter, even if it is only slightly so.

I queried this with Garmin and got a total non-answer. I asked the difference between bus, car, etc and was told that there was effectively no difference. I have tried changing the vehicle type and it makes no noticeable difference to Arrival time. I am afraid that vehicle type is a somewhat useless feature. Having said that the device does seem to learn your driving style over a period, as Swing says, though this was vehemently denied by the Garmin "expert".

Sometimes my wife, who was map-reading, would query the suggested route and, on one occasion, a longer route was suggested which seemed to have no merit at all until we entered the new motorway, not shown on my older Michelin map!

Another oddity is that the unit does seem to "learn" from repeated ignoring of its very local routes and will - eventually - direct you by the route that you habitually take - or at least that is what seems to happen!

My unit has now been returned because of the appalling TMC performance. I await better reports on this forum and when those are forthcoming will have no hesitation in buying another Garmin.

[footix2]

There is an option buried somewhere to avoid unpaved roads, which isnt set to yes as a default.

It does route quite strangely though on occasion.

The TMC is somewhat scatty too

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