Sat Nav Misses Junctions

[Stevex]

I have a 56 reg Prius Spirit bought a few months ago. It has the Sat Nav built in, which is great for me as I don't often go to unfamiliar places so figured I wouldn't need the latest and greatest.

However, I have noticed it completely misses road junctions out, both in the spoken directions and in the magnified display of the upcoming junction, although the main map is correct.

For example, I used it to see how it would cope with a short 2 mile journey through town I regularly make.

As I approach a 4 way set of traffic lights where I need to go straight on, nothing. But there is a "right turn" a few hundred yards ahead where the road just goes right anyway. But then, the next set of lights where you must turn left (and it shows on the main map), absolutely nothing, except just before it she tells you to turn right in a few hundred yards, which is what you do at the next set of lights after this one!

A similar thing happened when we went to visit friends in another town. I was at a T junction where I knew I had to turn right and all she said was to turn left at the roundabout, which came next.

Her distances to junctions she mentions are correct, it's just that she seems to be pretty clueless about the existence some of them. Have I messed up the SatNav somehow? I did replace the DVD with the latest 2009-2010 E12 one as I agreed with the dealer to include it in the purchase price.

Surely it can't be this bad.

[Sagitar]

I have noticed it completely misses road junctions out,

Mine does the same thing, but then so does the TomTom that I also use on occasion.

I suspect that it is something to do with road numbering and the fact that "say" an A-road passing through a town follows a number of smallish local roads that have junctions that the map producer simply treats as bends in the A-road and therefore does not mention.

The opposite also happens. Sometimes, what was once a local junction, is worked upon in widening the A-road to the point where it is no longer recognisable as a junction and yet the map continues to show it as such. So you get an instruction to turn right when all that you are really required to do is follow the A-road round a bend to the right.

The mappers job is quite difficult and his treatment of a junction may look very odd if you do not know the history of the way it has developed over time. In the end, you have to keep your wits about you and not depend too much upon a single instruction.

Having said all of that I still get led astray on occasion.

[Stevex]

Bends in the road and changes in junction layouts I can understand, and you can't beat a bit of common knowledge and common sense when using these things!

However, I've had a few SatNavs, including a built-in one like the Prius, but have never known them to be looking ahead past the junction I am approaching as if I'd already done it. Half expecting her to say "Well done, you turned left at those lights without me saying a word!"

[Jan&tone]

Satnav's always miss something!

There are two roundabouts on the A1 south of Grantham which are no longer there - the satnav still advises that it's a good idea to take the 2nd exit from both of them!

It's understandable really, the satnav is only human after all, and as we know, humans make mistakes! it's only computers that don't....

There's another thread somewhere about satnavs on the Prius and Auris (and presumably on the other models of Mr T's (certainly on my old Avensis) and as was said on there, they are for the guidance of wise men and the obedience of fools! Use them when you get to the vague area of your destination, but use common sense to get you to the vague area!

[Stevex]

Thanks for the replies. It looks like I've not set something wrong then, just won't expect her to be aware of junctions that have been there for 30+ years and are still there. At least the map is pretty up to date! :)