Portable Satellite Navigation Units
in [Aussie Drivers]
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From: John_H on 5 Apr 2010 19:51 D Walford wrote: >On 4/04/2010 1:55 PM, John_H wrote: >> Dingo wrote: >>> >>> I have a friend who was driving to Sydney from Goulburn via the back >>> way (using a cheap sat-nav with maps not updated) who ended up in the >>> middle of the prison farm out Shooters Hill away and had to explain to >>> a couple of guards that he wasn't there to spring someone. >> >> It probably wouldn't matter how much he paid for the sat nav, or how >> recent its maps were. None I've come across will reliably navigate >> away from cities, towns or main roads even though the minor roads and >> tracks are all mapped. Their only use in such localities is knowing >> where you are on the map... ie they'll tell the name of the road >> you're on, if it's got a name, but certainly not the best way >> (quickest or shortest) to get where you want to go. >> >> One of the quirks I've also come across is that they'll send you down >> a private road, fire track, or whatever, if it happens to link to the >> nearest main road. Which could lead to some tricky situations if the >> track's owners happen to shoot trespassers and prosecute survivors. >> >On the other hand mine has found address's in places where I didn't >think it possible, I've found farms 80klms from the nearest town >(Hopetoun in the Mallee) and more than half that distance on gravel roads. As will frequently be the case... but you can't rely on it. You don't say which side of Hopetoun, but I'd suggest next time you're at one of those farms try navigating from there to Swan Hill (which is three main roads removed from Hopetoun). My guess is it will stuff up badly and take you a very long way around... unless of course there's a main road joining the two which wasn't there the last time I was in those parts. :) As an example, I've got a mate who lives on a rural property on a minor road in the Atherton Tablelands (inland from Cairns, Q). The one way trip is slightly under 900km from my front door by the shortest practical route, which happens to be via the nearest main road and other main roads that connect to it, except for the final (short) leg. The Garmin will take me straight to his front gate by that route. OTOH my closest town is around 50km from my front door as the crow flies. Shortest route (all bitumen) is around 60km. Both the Garmin and the TomTom will choose an alternative route of around 75 km, via the nearest main road, and take twenty minutes longer to get there. >I often wonder if its navigates the shortest route so I usually ask the >farmer what's the quickest way back to town and more than once its been >the reverse of the way the GPS sent me. It will always take the shortest route when it's the only route, and the road or track is on its map, otherwise it appears to use some method for deciding which are priority roads and will navigate by those in preference to what it judges to be minor roads. Once outside towns it doesn't matter whether it's set for the shortest route or the quickest, it will still make the same choice. If you deviate from the chosen route, because you happen to know a better one, sometimes it will recalculate for the new route you choose... more often it will tell you to do a U-turn (if it's set to allow U-turns). >I know they are far from perfect but in most case they will navigate to >your destination and if you didn't know the area you wouldn't know you >had gone the long way:-) If the difference is only a few k's that will probably be the case, and the same thing also happens in towns, but I've encountered plenty of instances in country areas where the difference is hundreds of k's and frequently more than twice the distance by the shortest practical route. -- John H
From: Kev on 5 Apr 2010 22:29 John_H wrote: > D Walford wrote: >> On 4/04/2010 1:55 PM, John_H wrote: >>> Dingo wrote: >>>> I have a friend who was driving to Sydney from Goulburn via the back >>>> way (using a cheap sat-nav with maps not updated) who ended up in the >>>> middle of the prison farm out Shooters Hill away and had to explain to >>>> a couple of guards that he wasn't there to spring someone. >>> It probably wouldn't matter how much he paid for the sat nav, or how >>> recent its maps were. None I've come across will reliably navigate >>> away from cities, towns or main roads even though the minor roads and >>> tracks are all mapped. Their only use in such localities is knowing >>> where you are on the map... ie they'll tell the name of the road >>> you're on, if it's got a name, but certainly not the best way >>> (quickest or shortest) to get where you want to go. >>> >>> One of the quirks I've also come across is that they'll send you down >>> a private road, fire track, or whatever, if it happens to link to the >>> nearest main road. Which could lead to some tricky situations if the >>> track's owners happen to shoot trespassers and prosecute survivors. >>> >> On the other hand mine has found address's in places where I didn't >> think it possible, I've found farms 80klms from the nearest town >> (Hopetoun in the Mallee) and more than half that distance on gravel roads. > > As will frequently be the case... but you can't rely on it. > > You don't say which side of Hopetoun, but I'd suggest next time you're > at one of those farms try navigating from there to Swan Hill (which is > three main roads removed from Hopetoun). My guess is it will stuff > up badly and take you a very long way around... unless of course > there's a main road joining the two which wasn't there the last time I > was in those parts. :) > > As an example, I've got a mate who lives on a rural property on a > minor road in the Atherton Tablelands (inland from Cairns, Q). The > one way trip is slightly under 900km from my front door by the > shortest practical route, which happens to be via the nearest main > road and other main roads that connect to it, except for the final > (short) leg. The Garmin will take me straight to his front gate by > that route. > > OTOH my closest town is around 50km from my front door as the crow > flies. Shortest route (all bitumen) is around 60km. Both the Garmin > and the TomTom will choose an alternative route of around 75 km, via > the nearest main road, and take twenty minutes longer to get there. > >> I often wonder if its navigates the shortest route so I usually ask the >> farmer what's the quickest way back to town and more than once its been >> the reverse of the way the GPS sent me. > > It will always take the shortest route when it's the only route, and > the road or track is on its map, otherwise it appears to use some > method for deciding which are priority roads and will navigate by > those in preference to what it judges to be minor roads. Once outside > towns it doesn't matter whether it's set for the shortest route or the > quickest, it will still make the same choice. If you deviate from the > chosen route, because you happen to know a better one, sometimes it > will recalculate for the new route you choose... more often it will > tell you to do a U-turn (if it's set to allow U-turns). > >> I know they are far from perfect but in most case they will navigate to >> your destination and if you didn't know the area you wouldn't know you >> had gone the long way:-) > > If the difference is only a few k's that will probably be the case, > and the same thing also happens in towns, but I've encountered plenty > of instances in country areas where the difference is hundreds of k's > and frequently more than twice the distance by the shortest practical > route. > What have you got them set to for navigation route options? Kev
From: John_H on 6 Apr 2010 01:26 Kev wrote: >John_H wrote: >> D Walford wrote: >> >>> I know they are far from perfect but in most case they will navigate to >>> your destination and if you didn't know the area you wouldn't know you >>> had gone the long way:-) >> >> If the difference is only a few k's that will probably be the case, >> and the same thing also happens in towns, but I've encountered plenty >> of instances in country areas where the difference is hundreds of k's >> and frequently more than twice the distance by the shortest practical >> route. > >What have you got them set to for navigation route options? For the Garmin when used outside towns and cities, best choice for me is usually (but not always).... Route preference: Faster time No avoidances. FWIW most of the options, including shortest route instead of faster time, make no difference to on road navigation outside towns and cities. The most notable exception is having it set to avoid U-turns, which will sometimes (but not always) force it to recalculate an alternative route which it won't otherwise do of its own accord. Whatever the settings, in unfamiliar remote locations it _always_ pays to check the direct distance to the destination against the route the sat nav wants to take. If the difference is large, and there's no obvious geographical reason, then there's probably a better way to go. -- John H
From: D Walford on 6 Apr 2010 05:22 On 6/04/2010 9:51 AM, John_H wrote: > D Walford wrote: >> On 4/04/2010 1:55 PM, John_H wrote: >>> Dingo wrote: >>>> >>>> I have a friend who was driving to Sydney from Goulburn via the back >>>> way (using a cheap sat-nav with maps not updated) who ended up in the >>>> middle of the prison farm out Shooters Hill away and had to explain to >>>> a couple of guards that he wasn't there to spring someone. >>> >>> It probably wouldn't matter how much he paid for the sat nav, or how >>> recent its maps were. None I've come across will reliably navigate >>> away from cities, towns or main roads even though the minor roads and >>> tracks are all mapped. Their only use in such localities is knowing >>> where you are on the map... ie they'll tell the name of the road >>> you're on, if it's got a name, but certainly not the best way >>> (quickest or shortest) to get where you want to go. >>> >>> One of the quirks I've also come across is that they'll send you down >>> a private road, fire track, or whatever, if it happens to link to the >>> nearest main road. Which could lead to some tricky situations if the >>> track's owners happen to shoot trespassers and prosecute survivors. >>> >> On the other hand mine has found address's in places where I didn't >> think it possible, I've found farms 80klms from the nearest town >> (Hopetoun in the Mallee) and more than half that distance on gravel roads. > > As will frequently be the case... but you can't rely on it. > > You don't say which side of Hopetoun, but I'd suggest next time you're > at one of those farms try navigating from there to Swan Hill (which is > three main roads removed from Hopetoun). My guess is it will stuff > up badly and take you a very long way around... unless of course > there's a main road joining the two which wasn't there the last time I > was in those parts. :) It was roughly NE of the town. I've never had noticed of the problems you describe but I've mainly used it in Victoria where the distances between places is usually a lot shorter than where you are so if it does stuff up its not such a big deal. One place it seems to get confused is in the Dandenongs, I've been up there a few times recently for work and a couple of weddings and finding anything in that area is a nightmare and the GPS seems to make it even more so. Daryl
From: John_H on 6 Apr 2010 06:45
D Walford wrote: >On 6/04/2010 9:51 AM, John_H wrote: >> D Walford wrote: >>> >>> On the other hand mine has found address's in places where I didn't >>> think it possible, I've found farms 80klms from the nearest town >>> (Hopetoun in the Mallee) and more than half that distance on gravel roads. >> >> As will frequently be the case... but you can't rely on it. >> >> You don't say which side of Hopetoun, but I'd suggest next time you're >> at one of those farms try navigating from there to Swan Hill (which is >> three main roads removed from Hopetoun). My guess is it will stuff >> up badly and take you a very long way around... unless of course >> there's a main road joining the two which wasn't there the last time I >> was in those parts. :) > >It was roughly NE of the town. I'd assumed you'd almost certainly be NW of Hopetoun, which is a relatively remote area by Vic standards, and probably one of the few places in Vic where you could be as far as 80km from the nearest town. How can the nearest town be Hopetoun if you're 80 km to the NE of it? By my rough arithmetic, and with the help of an ancient Vic roadmap, Lascelles is about 30km NE of Hopetoun and Sea Lake is around 60km NE. 80km would put you east of Lake Tyrrell and the nearest town would be Chinkapook. You would also have crossed two main roads since leaving Hopetoun (Sunraysia and Calder Highways). Assuming you've got the distance and direction right, if you were to navigate back to Melbourne (or come the other way) a sat nav would almost certainly send you to Nyah, on the Murray Valley Highway, and back to Melbourne via Swan Hill and Bendigo. If you tried to navigate back to Hopetoun from Chinkapook it wouldn't have any difficulty finding Hopetoun but I'd be very surprised if it sent you by anything like the shortest route. -- John H |