| View previous topic :: View next topic |
| Author |
Message |
ride4smilesjonny
Regular Visitor
Joined: Dec 29, 2005
Posts: 222
Location: teesside
|
 Posted: Thu Feb 23, 2006 4:57 pm Post subject: |
 |
|
| ride4smilesjonny wrote: | | Lester did you ever get to try two units side by side? |
Take that as a no then! 8O
_________________
**********************************
Hi ho - Hi ho its off to Arran i go,
with my i3 and a cup of tea hi ho, hi ho
hi ho hi ho.....
**********************************
www.ride4smiles.co.uk
£3500 raised in two weeks! :-) |
|
| Back to top |
|
 |
swing
Pocket GPS Verifier
Joined: Nov 04, 2003
Posts: 2225
Location: Bedfordshire, UK
|
| Posted: Thu Feb 23, 2006 5:06 pm Post subject: |
|
|
| Lester_Burnham wrote: | I'm not talking about route alternatives on fairly local roads.
I'm talking about a difference in the route 15, 20, or 25 miles away.
Clearly with variable start points, local aspect of a route may vary - no problems with that.
What I'm talking about is a fairly obvious route, with main motorway segments, and variation in the motorways / junctions used, some distance into the journey. |
I do understand that, and I appreciate the example I have regularly seen appears to be locals roads - but it is answering the earlier posts - a difference of a few yards can create a large effect on the planned route - in my case from the very first junction.
I've certainly seen TomTom offer one route to a location, yet a different route on the way back. Also, I've seen TomTom affected by stretches of one way roads / dual carriageway with limited junctions such that different routes are calculated based on the direction of travel.
Having done some "simple" studying of the logic and formulae involved in these calculations a fair few years back, I can tell you I think it's a miracle these devices can produce a route at all!
So, yes, I would expect differences with the route offered, but, as others seems to have reported, I would expect from the *same* start point to the *same* destination I would expect a consistent route. |
|
| Back to top |
|
|
Lester_Burnham
Frequent Visitor
Joined: Oct 17, 2005
Posts: 618
|
| Posted: Thu Feb 23, 2006 5:22 pm Post subject: |
|
|
| swing wrote: | | Lester_Burnham wrote: | I'm not talking about route alternatives on fairly local roads.
I'm talking about a difference in the route 15, 20, or 25 miles away.
Clearly with variable start points, local aspect of a route may vary - no problems with that.
What I'm talking about is a fairly obvious route, with main motorway segments, and variation in the motorways / junctions used, some distance into the journey. |
I do understand that, and I appreciate the example I have regularly seen appears to be locals roads - but it is answering the earlier posts - a difference of a few yards can create a large effect on the planned route - in my case from the very first junction.
I've certainly seen TomTom offer one route to a location, yet a different route on the way back. Also, I've seen TomTom affected by stretches of one way roads / dual carriageway with limited junctions such that different routes are calculated based on the direction of travel. |
Yup - no problem with that - with more thought, it's reasonable to understand symmetrical routes.
| swing wrote: | | So, yes, I would expect differences with the route offered, but, as others seems to have reported, I would expect from the *same* start point to the *same* destination I would expect a consistent route. |
Me too - but I'm not.
I can see how slight variances may affect what some see as local parts of the route - that's reasonable and natural to understand.
What I don't see as following any logic is such variations, then affecting something quite a bit later on in a common route.[/i] |
|
| Back to top |
|
|
Lester_Burnham
Frequent Visitor
Joined: Oct 17, 2005
Posts: 618
|
| Posted: Thu Feb 23, 2006 5:24 pm Post subject: |
|
|
| Lester_Burnham wrote: | | Yup - no problem with that - with more thought, it's reasonable to understand symmetrical routes. |
Sorry, that should read asymmetrical (one of the downsides to the lack of post edit facilities). |
|
| Back to top |
|
|
bumpkin
Frequent Visitor
Joined: Feb 08, 2006
Posts: 264
Location: Herefordshire
|
| Posted: Thu Feb 23, 2006 6:21 pm Post subject: |
|
|
| Lester_Burnham wrote: | | Sorry, that should read asymmetrical (one of the downsides to the lack of post edit facilities). |
Sorry, slightly off topic: Is there a reason that this forum lacks this facility? All the other forums I frequent have the capability to edit posts.
_________________
Chas
Garmin i3, Quest & StreetPilot 2720 with GTM10 |
|
| Back to top |
|
|
swing
Pocket GPS Verifier
Joined: Nov 04, 2003
Posts: 2225
Location: Bedfordshire, UK
|
| Posted: Thu Feb 23, 2006 6:42 pm Post subject: |
|
|
| Lester_Burnham wrote: | | What I don't see as following any logic is such variations, then affecting something quite a bit later on in a common route. |
I agree it's not intuitive - but remember the unit will consider the whole journey, not sections. However, I think I agree that a difference of a few hundred yards shouldn't be seen to be making a difference many miles into a common route. Although mathematically it may be correct, it's certainly not what the consumer would expect to happen. |
|
| Back to top |
|
|
swing
Pocket GPS Verifier
Joined: Nov 04, 2003
Posts: 2225
Location: Bedfordshire, UK
|
| Posted: Thu Feb 23, 2006 6:45 pm Post subject: |
|
|
| bumpkin wrote: | | Is there a reason that this forum lacks this facility? |
A few years back a forum upgrade required all the old messages to be manually imported - this resulted in the entries no longer being associated with the correct username. As such, if editing was enabled, if would be potentially possible to edit someone else's post. As such, editing is only turned on in very select conferences until a full solution can be found. At least that's what I think I remember reading on the subject - searching the general forums towards the top of the list of forums should confirm this. |
|
| Back to top |
|
|
mhb
Regular Visitor
Joined: Dec 21, 2005
Posts: 155
|
| Posted: Thu Feb 23, 2006 11:38 pm Post subject: |
|
|
| I really can't see that any of the reasons so far suggested by anyone could have caused what I experienced on the way back from Dundee. |
|
| Back to top |
|
|
ride4smilesjonny
Regular Visitor
Joined: Dec 29, 2005
Posts: 222
Location: teesside
|
| Posted: Thu Feb 23, 2006 11:43 pm Post subject: |
|
|
| mhb wrote: | | I really can't see that any of the reasons so far suggested by anyone could have caused what I experienced on the way back from Dundee. |
Not even the previous mentioned theory of the pixies  
_________________
**********************************
Hi ho - Hi ho its off to Arran i go,
with my i3 and a cup of tea hi ho, hi ho
hi ho hi ho.....
**********************************
www.ride4smiles.co.uk
£3500 raised in two weeks! :-) |
|
| Back to top |
|
|
rossb
Regular Visitor
Joined: Nov 17, 2004
Posts: 79
Location: Sheffield, UK
|
| Posted: Thu Mar 02, 2006 8:24 pm Post subject: |
|
|
I once experienced a very annoying route variance on my Streetpilot III. I was about to report a map error, then the unit took me on a different and correct route the following morning.
I believe variance could happen on any GPS unit, because GPS signals can never be a constant. There are many factors in GPS signal quality including weather, interference from environment/car, which satellite you lock on to etc. |
|
| Back to top |
|
|
Milkfloat
Regular Visitor
Joined: Jun 15, 2005
Posts: 61
|
| Posted: Fri Mar 03, 2006 11:28 am Post subject: |
|
|
| rossb wrote: | I once experienced a very annoying route variance on my Streetpilot III. I was about to report a map error, then the unit took me on a different and correct route the following morning.
I believe variance could happen on any GPS unit, because GPS signals can never be a constant. There are many factors in GPS signal quality including weather, interference from environment/car, which satellite you lock on to etc. |
This will not affect the routing algorithms. All the gps does is give a position. It would have to be hundreds of meters incorrect before routing is affected. |
|
| Back to top |
|
|
gcb
Regular Visitor
Joined: Oct 24, 2005
Posts: 151
|
| Posted: Mon Mar 06, 2006 11:50 am Post subject: |
|
|
CONSISTENT Routing problem.
Try setting a route to Europe and the C310 (at least) although it displays several ferry options will only ever choose the one route.
"i.e Dover to Calais using the Chunnel" - which it seems to think is a road?
I mean even if you tried to set a route from Ramsgate to Osteend it would still tell you to drive down to Dover and drive from Calais to Osteend? Realise its not that important but just thought Id mention it. |
|
| Back to top |
|
|
Skippy
Pocket GPS Verifier
Joined: 24/06/2003 00:22:12
Posts: 2946
Location: Escaped to the Antipodies! 36.83°S 174.75°E
|
| Posted: Mon Mar 06, 2006 2:48 pm Post subject: |
|
|
| gcb wrote: | Try setting a route to Europe and the C310 (at least) although it displays several ferry options will only ever choose the one route.
"i.e Dover to Calais using the Chunnel" - which it seems to think is a road?
I mean even if you tried to set a route from Ramsgate to Osteend it would still tell you to drive down to Dover and drive from Calais to Osteend? Realise its not that important but just thought Id mention it. |
Ramsgate to Oostende ferry isn't marked on the Mapsource maps (v7 anyway) and that is why it won't route using it.
The Channel tunnel is marked as a ferry, the same as the Dover to Calais route.
The ferry speed is set at 12 MPH so when you ask for the "Fastest" route, you will always get the shortest ferry journey possible. Try Portsmouth to LeHarvre - it may route you to Dover to catch the ferry there. 
The best thing to do is plan your ferry crossing in advance and route to your chosen ferry port then route on to your destination.
_________________
Gone fishing! |
|
| Back to top |
|
|
gcb
Regular Visitor
Joined: Oct 24, 2005
Posts: 151
|
| Posted: Mon Mar 06, 2006 4:40 pm Post subject: |
|
|
Its all hyperthetical because of course yes you would plan the route to the ferry terminal not the destination I agree.
However the point still stands
I challenge you to get the Garmin unit to calculate just one route to Europe that does not go by Chunnel. Try Newcastle on Tyne to Bergen?
I havent tried these but I bet it still recomends the Chunnel. Helsinki,Riga,Mosco. |
|
| Back to top |
|
|
Milkfloat
Regular Visitor
Joined: Jun 15, 2005
Posts: 61
|
| Posted: Mon Mar 06, 2006 8:45 pm Post subject: |
|
|
| gcb wrote: | Its all hyperthetical because of course yes you would plan the route to the ferry terminal not the destination I agree.
However the point still stands
I challenge you to get the Garmin unit to calculate just one route to Europe that does not go by Chunnel. Try Newcastle on Tyne to Bergen?
I havent tried these but I bet it still recomends the Chunnel. Helsinki,Riga,Mosco. |
As Skippy said, the Channel Tunnel is coded as a ferry route and as such has a low speed category like other ferries. Therefore it will always use the route that is fastest. Newcastle to Bergen at 12mph will take a very long time, so it may well route via Dover - Calais. |
|
| Back to top |
|
|
|
![]() Posted: Today Post subject: Pocket GPS Advertising |
|
|
We see you’re using an ad-blocker. We’re fine with that and won’t stop you visiting the site.
Have you considered making a donation towards website running costs?. Or you could disable your ad-blocker for this site. We think you’ll find our adverts are not overbearing!
|
|
| Back to top |
|
|
|
Forum FAQ
Search
Usergroups
Profile
Log in for private messages
Log in
