Thread: In Car GPS

That people have the knowledge of the road to be able to do a better job of selecting a route than the GPS. I still argue that if you can do that, there's hardly any point in switching the thing on.

Not quite what I am suggesting. I *check* the route on the laptop, I don't write the whole thing from scratch unless working out a delivery route or something like that. The check is usually just a quick scan to see if there are anomalies, these are very easy to detect on a big screen and only takes seconds. Again, this is only for long trips.

By the way, mine will select the quickest route or the shortest route or the route that avoids tolls or a walking route etc. The shortest by distance is not necessarily the quickest as it appears on the map and it has an algorithm for working that out somehow. If I just look at a map overview, I might be tempted to take what appears to be the shortest route, without the knowledge of the local conditions required to say if it is actually the quickest. This is especially true in cities.

Most units have had those functions as standard for years. What do you do if you go on a long trip and forget you have "avoid tolls" set? I don't think I would want to traverse Sydney blindly avoiding tolls in peak hour, a scan beforehand would have made it pretty clear there was something amiss. This is only a very simple example though. For me and the way I travel, I have found it pays to do a quick check, rather than try to recover AFTER some problem is found.

I was just trying to make the point that the quickest route is not necessarily the shortest as it appears on the map and the unit makes this distinction (if you tell it to). Reading a flat map without local knowledge, I would not be able to do the same. Distance-wise from here to Sydney, the coast road is shorter, but the quickest route is inland because of the motorway. If I was looking at a road map, I would be tempted to travel up the coast and not even consider the Hume, but good old Tom Tom dialled that up as the first choice.

I leave it on Quickest Route all the time. If there are tolls, it warns you and you can at that point ask it to give you an alternative avoiding the tolls. It shows you the new route time and distance compared to the old and you can revert or accept the new route. Fantastic gadgets

It's not the idea of checking the route that I'm objecting to - you're free to do that if you want, it's your assertion that those of us blindy accepting the route are not using these units correctly. I think this is exactly how they should be used, but you always have the option to manually check it yourself if you want.

I wouldn't be trusting my old clunker for this trip, or any other new one for that matter.

What's the problem? There's only one road

I think that sort of trip is outside the scope of these things. If you only took a Tom Tom on a trip like that and were never seen again, nobody would be surprised.

Six people leave Oodnadatta for Birdsville, each with their own unit, each unit gives a slightly different route - why? Each person is trusting their unit. You can see that Rob's unit and my unit give two very different routes between Oodnadatta and Birdsville - whose is correct? Mine is shorter. Neither in this case, human intervention and assessment is clearly required.

By using the GPS the wrong way I was questioning (in my mind) the blind trust put in their output. There have already been a number of statements by others where they had issues with the units, I'm simply saying a common sense check should be applied. The units are quite accurate for positioning but are not infallible with route creation.

EDIT: Just saw your reply to Rob. Change the example above for a trip from a suburb in Melbourne to a Sydney or Adelaide suburb, variations would still be there.

Out of interest I ran the route from you to Sydney (Opera House). Garmin says take the coast road. Autorouting on and fastest time selected.

We seem to be going around in circles. Maybe we need a navigator to find a way out of this argument

What I'm saying is that, without local knowledge of the roads, I can't know beforehand that the GPS has got it wrong, so it's fairly pointless giving it any more than the most cursory of glances before setting off, because I'm not equipped with the knowledge I need to correct any problems at the outset.

If I was able to do that, I wouldn't need the GPS. The only alternative for me is to put my faith in it and it's ability to get me where I want to go one way or another, hopefully in the quickest fashion, road changes and my own capability to follow the instructions given notwithstanding.

People often give me directions and I've forgotten them after the first right turn (are you reading this Peter?). I simply dial up where I want to go, and it tells me. If I miss a turn or the turn doesn't exist, the Tom Tom, rather than flying into a panic, calmly recalculates a new course on the spot. "Never mind", it says in its lilting Irish accent, "in eight hundred metres, turn left, then go through the rindabite, second exit". It is so confident and calming, you can't help but put your faith in it. I wish they were available for more things in life

Let me say first of all that I don't own a GPS, nor have I ever used one.

However, if they work the same as Whereis and Google Maps on the web then I wouldn't put blind faith in them either.

To give you an example, I needed to go to Mt Gambier in SA from Bendigo. I asked Whereis for a suggested route and it tried to send me down to Ballarat then on the Western Hwy to Arrarat, then Hamilton and Mt Gambier. I raised my eyebrows at this and asked Google Maps.

It came up with Bendigo-Maryborough-Avoca-Arrarat-Hamilton-Mt Gambier, shorter by some 80kms! BTW it was the route I had selected by looking at one those "old fashioned" things called a map.

I had a similar experience when I asked for directions to Lara from Bendigo.

So, as I said if these new fangled GPSs work on the Whereis and Google maps, then I certainly wouldn't have blind faith in them, I'd still be checking against a map or other knowledge.

No they are not the same as Whereis.

OK, I'm over this argument. Obviously there are going to be people who don't trust them, I'm not going to try and convince you. If you don't trust them, then don't buy one. Just don't tell me that I'm using mine incorrectly or that I shouldn't put blind faith in it and then we'll all be happy, OK?

Here is an actual example (Kiwibrucee was with me at the time) of a GPS getting it clearly wrong. Look at Launching Place, the purple is the route taken as told by the GPS. If I had looked at the route on the laptop - where the screenshot is from - it would have been clear there was something funny there and I could have corrected it. This is only a few kilometers and a few minutes, but is the only example I have with a member as witness.

Roughly the track across the Simpson I have drawn in red on Groggy's map.

The internet and the GPS both did not offer the French Line or the Rig Rd.

It does not surprise me, these are tools for navigating around cities and regional areas not for areas a bit more remote.

To go into the Simpson with only a Road type GPS expecting to navigate would be foolish. You need maps, compass and a GPS like mine or one of the new ones where you can upload your maps. I would not rely solely on any GPS out there.

As there are only about 3 crossroads out there, it would be difficult to get lost but it is good to check your progress and confirm you are on the track using my GPS and maps.

This has been a very interesting thread.

I definitely won't be buying a Road GPS and for the minor inconvenience of wasting a minute here and there with my PC and old GPS I will not be getting lost.

If I was regularly driving in built up areas (cities and large towns) that were unfamiliar to me then I think one of the Road type GPS's would be quite handy.

Who decides what maps are available, some indoors geek or some con artist marketing wimp? Are any of them aussies?

Here is an actual example

I just plugged in a route from Woori Yallup to Yarra Junction and it took me straight through using your route marked with the red line.

So maybe the problem here is not GPS in general but your unit in particular?

Out of interest I ran the route from you to Sydney (Opera House). Garmin says take the coast road. Autorouting on and fastest time selected.

I asked Tom Tom for a route to Sydney CBD and it goes via Canberra, which is 6:00 hours - 522km. Calculate alternative gives the coast at 6:19 hours - 454km.

Originally Posted by Big Shed

To give you an example, I needed to go to Mt Gambier in SA from Bendigo. I asked Whereis for a suggested route and it tried to send me down to Ballarat then on the Western Hwy to Arrarat, then Hamilton and Mt Gambier. I raised my eyebrows at this and asked Google Maps.

It came up with Bendigo-Maryborough-Avoca-Arrarat-Hamilton-Mt Gambier, shorter by some 80kms! BTW it was the route I had selected by looking at one those "old fashioned" things called a map.

Tom Tom gave me the Bendigo-Maryborough-Avoca-Arrarat-Hamilton-Mt Gambier first time.

Originally Posted by silentC

I just plugged in a route from Woori Yallup to Yarra Junction and it took me straight through using your route marked with the red line.

So maybe the problem here is not GPS in general but your unit in particular?

It is an example for a particular GPS (phone) I used for the purpose of illustrating how quickly errors can be seen on the screen. My wife's Tom Tom unit had no problem and the Streetpilot also does not repeat the error.

This is why I said "If I had looked at the route on the laptop - where the screenshot is from - it would have been clear there was something funny there and I could have corrected it."

The point is that ALL units will have errors in them somewhere and a quick check on a larger screen makes any error pretty clear. Any error found on a given unit is unlikely to be found on other units unless they use the same software.