OT Sat Nav

[fred]

What I want is a Satnav I can plug into my computer and check the route it is suggesting or even download the journey I have set up in Google Earth/Maps. Save some of those stupid routes Satnavs come up with.

Satnavs can be a right pain in the ass. We recently missed a turning in the city of Ourense, northern Spain, and the Garmin took us on an incredible journey up and down unpaved roads, dirt tracks really, all within a short distance of the city centre. It did eventually get us there but at much expense of nerve and concern about the hire car.

Paul Mc Cann

[djc]

I have learnt not to set 'shortest route', 'slow car' when driving in Italy. I have ended up in a field where the track just disappeared.

[djc]

GPS speed is usually very accurate when cruising along. But is there is a poor signal then both the position and speed indication can be erratic. On a car GPS the position is locked to the road unless you set it for 'pedestrian' so it can look more accurate than it is.

[Steve Firth]

Heh. Experienced that a lot and I've seen many, usually foreign, drivers coming down the mile or so of private road that leads from my house to the local village (in Italy). The problems is that sat nav shows the road as open at each end whereas it's closed by the presence of two farms, mine and my neighbour's, and the link between the two sections of road is a goat track. It's even funnier if they try either of the two other roads that satnav shows as ways off my road. One of them leads down through a vineyard that is planted on a hill so steep that it's almost a cliff. I can get down and up it in a 4x4 with a low ratio box, I wouldn't try it in a saloon car. The other is a road that starts off looking reasonable that then goes over the edge of a cliff and ends up in a swamp. I've never done that one in a wheeled vehicle, but I have done it in a tracked tractor and even then it was bloody scary. My neighbour said he once pulled a Fiat Punto back up that road after the driver had slavishly followed sat nav to try and reach a restaurant on the other side of the slope and avoid a two mile drive around the swamp.

[charles]

but if the dongle protruses too far back, you have difficulty (sometimes) in fitting one. Then you need a "dongle dangler".

[Robin]

Mercedes Benz also state: "DISTRONIC does not always detect complex road and traffic situations properly. You could then get an incorrect distance warning signal or no distance warning signal at all." IMHO Hanger Lane Gyratory usually counts as "complex" ;)

There are also other tests which suggest that the technology may not yet be up to replacing conventional speedometers: eg

Which is no criticism of the technology as it's not (yet) intended to do so.

[Tim Streater]

If one were to contest such a case, does one have access to these photos?

[Steve Firth]

Yes, but usually only after you have decided to take the case to court. Most police forces won't supply copies to anyone who asks to see them at the time they receive the NIP, but there is a right to see the photo if one is determined to contest the case in court. Of course if one is guilty as charged then opting to go to court will cost a lot more than £60.

[ARWadsworth]

I did receive a NIP after a GATSO flashed me. I knew I was not speeding and apart from the legal bit ie supplying the details of the driver I just ignored all the other letters that arrived as they gave me no opportunity to see the photos or plead not gulty. I even received a reminder saying I could pay by credit card to avoid a court case after the cut off date. That was the last I ever heard of the case.

[Nightjar]

IME the warnings are rather over cautious, as might be expected. It has, for example, never failed to detect a motor bike, which is one of the warnings given. Not that I would try to rely upon it at Hanger Lane. For one thing, it leaves a much larger gap ahead than most other drivers like to see left empty.

As I said, it will only brake automatically at up to 40% and anything harder does need driver intervention, which is what that video demonstrates. The first attempt at 80mph was obviously done with the follow distance wound down to the minimum, while the second was with it set to a much greater distance. However, looking at the display on the first attempt, the cars are only about 40 yards apart and I don't think my system would let me be that close at the indicated 70mph (the 80mph in the centre is the target speed, not the actual), so the system may have been modified since that car was registered in 2006.

Colin Bignell

[dennis]

Tomtoms are locked to the road and are not as accurate for speed as a result. the data logger I carry in my pocket is far more accurate for speed but the position can sometimes be slightly off the road according to Google.

The guy that claims his invention can position a phone to 0.5m is talking bull. Its easy enough to do using differential GPS and correcting it to a known ground station. its a common application and is quite easy to do by connecting over the data network to a reference machine to correct the errors. I do hope that's not what he thinks he has patents on or he is wasting his time.

[dennis]

Over inflation will make the error the opposite of under inflation.

Mine is 2 mph over at 30 mph, 3 at 50 mph, 5 at 70 mph, and 5 at 90mph.

[dennis]

Tomtoms are very good at selecting routes, especially if you have a "live" one which can actually find out about current jams rather than just past jams. There really isn't a better satnav for use in the UK as far a route planning goes.

[Tim Streater]

Mmmm, so if you feel you were not guilty you have to risk laying out a lot of dosh in order to know whether you were in fact speeding or whether in fact it's a camera operator c*ck-up. This is hardly justice.

[Dave Plowman (News)]

Really? Can you give some accurate figures for this?

[The Medway Handyman]

How would you know? You never drive at over 30mph.

[Ret.]

See below:

Possibly - although I have yet to come across a UK car that does not over-read. I suspect that the odd one that is 100% accurate is, in fact, 'faulty' - in that it was actually designed to over-read!

Exactly - which is why they are manufactured to over-read in the EU - but to be accurate in the US.

[Ret.]

Which, IME, is generally par for the course for EU produced vehicles...

[ARWadsworth]

Maybe it is not justice but I am sure dennise will soon tell you that you should never break the speed limit.

[ARWadsworth]

I stand corrected:-)