View previous topic :: View next topic |
Author |
Message |
hypnotist Occasional Visitor

Joined: Jul 18, 2017 Posts: 10
|
Posted: Thu Dec 14, 2017 2:39 pm Post subject: Garmin back to TomTom (because of bad Cornwall routing) |
|
|
Early this year my ageing TomTom Start 20 was really due for a upgrade and I bought Garmin Drive 50, as the months have progressed I found it bizarre some of the routes it was taking me down (Cornwall), when there was a very direct route available. Decided the maps in Cornwall left a bit to be desired (latest maps) so had a good deal on a TomTom Start 25 with lifetime maps and being Nav3 able to load Pocket GPS Speed Camera data base.
I understand the newer TOMTOMs with nav4 you can't load custom POIs which is why I bought the Start 25, looks like TomTom want users to buy their speed camera database?
Already pleased with the start 25, sorry but the Garmin didn't do very well down in Cornwall. |
|
Back to top |
|
 |
Privateer Pocket GPS Moderator


Joined: 30/12/2002 17:36:20 Posts: 4921 Location: Oxfordshire, England, UK
|
Posted: Mon Jan 22, 2018 9:31 pm Post subject: |
|
|
Hi hypnotist,
We're currently in Cornwall for a few days and have been comparing my newish (i.e. Had since October 2017) Garmin 770 Camper LMT-D against TomTom iOS GO Mobile, which is an extremely poor app but if you use POIVeiwer for POIs it'll route fairly reasonably.
First off the Garmin's routing was awful as it used strange narrow lanes and kept routing you off the direct route only to be routed back onto the original road a few miles later. How on earth Garmin think that this random change of roads actually gives you the fastest journey is beyond me.
The camper has the advantage of specifying the vehicle dimensions. I've tried a few different settings and here are some that so far seem to give reasonable routes i.e. Routes similar to what TomTom give:
Height: 8'
Width: 10'
Overall Lenght: 15'
Gross Weight: 2.0 t
Max Speed: 70 mph
I know that the above size is a weird pseudo vechile but it does seem to make a difference to the routing by avoiding unnecessary narrow lanes and changing roads too often.
I shall continue to experiment with the settings and it'll be interesting to see how they affect the routing when I'm back home.
Regards, _________________ Robert.
iPhone 6s Plus, iOS 14.0.1: iOS CamerAlert v2.0.7
TomTom GO Mobile iOS 2.3.1; TomTom (UK & ROI and Europe) iOS apps v1.29
Garmin Camper 770 LMT-D |
|
Back to top |
|
 |
Kremmen Pocket GPS Verifier


Joined: Mar 03, 2006 Posts: 7223 Location: Reading
|
Posted: Tue Jan 23, 2018 5:27 am Post subject: |
|
|
Given the number of Garmin routing issues we see here I wonder if they know and possibly don't care given the length of time we've known ? _________________ DashCam:
Viofo A119 V3 |
|
Back to top |
|
 |
sussamb Pocket GPS Verifier

![]()
Joined: Mar 18, 2011 Posts: 4462 Location: West Sussex
|
Posted: Tue Jan 23, 2018 7:36 am Post subject: |
|
|
I know others complain but I rarely see poor routing issues, either here or in France. Cornwall is full of minor roads so it's hardly surprising some are selected as it's often quicker. Looking at TT forums users there also complain of what they see as 'routing issues'. Some drivers of course don't like minor/narrow roads and I understand that. If you had an option to avoid narrow roads that would be good for some but I don't think there is any satnav manufacturer that offers that option on their 'bog standard models' so I guess there isn't sufficient demand?
Most Garmins these days can have viapoints added easily enough so it isn't too hard to force routes along main roads if that's what users prefer.
Camper versions of course allow you to 'dial out' narrow roads so they at least for those users shouldn't cause any issues. Using their settings to avoid other roads is an interesting idea, will be good to know how that works. _________________ Where there's a will ... there's a way. |
|
Back to top |
|
 |
AllanKnowles Occasional Visitor

Joined: Feb 06, 2005 Posts: 39
|
Posted: Tue Jan 23, 2018 8:02 am Post subject: |
|
|
It can be done. This is the reason I switched to Co-Pilot on a tablet. You can weight your road preferences so that you get sensible routing. |
|
Back to top |
|
 |
sussamb Pocket GPS Verifier

![]()
Joined: Mar 18, 2011 Posts: 4462 Location: West Sussex
|
Posted: Tue Jan 23, 2018 8:33 am Post subject: |
|
|
No good for me, for numerous reasons I prefer a dedicated device over any app either on phone or tablet. _________________ Where there's a will ... there's a way. |
|
Back to top |
|
 |
MaFt Pocket GPS Staff


Joined: Aug 31, 2005 Posts: 15388 Location: Bradford, West Yorkshire
|
Posted: Wed Jan 24, 2018 2:11 am Post subject: |
|
|
It's been a while since I've done Cornwall but I do recall many issues with my Garmin(s) down there compared to other areas.
My personal theory is that the narrow roads are, technically, 60mph speed limit so it assumes you can reach that speed - ergo it's a faster route.
It's been a while since I've used Garmin, do their maps have the equivalent to TomTom's where they log average speeds over time on each road?
MaFt |
|
Back to top |
|
 |
sussamb Pocket GPS Verifier

![]()
Joined: Mar 18, 2011 Posts: 4462 Location: West Sussex
|
Posted: Wed Jan 24, 2018 7:43 am Post subject: |
|
|
Garmin's 'learn' your driving style so if you travel narrow roads a lot they'll adjust the speed you travel roads with a 60mph limit down, although I suspect for the majority of us that only hit narrow roads occasionally this won't impact much on route choice if we travel to Cornwall only occasionally. _________________ Where there's a will ... there's a way. |
|
Back to top |
|
 |
arfurdent Regular Visitor
![]()
Joined: Mar 05, 2006 Posts: 116
|
Posted: Wed Jan 24, 2018 9:55 am Post subject: |
|
|
when on holiday down in Cornwall I notice that my trusty Tomtom 750 also gets confused by narrow roads with a 60mph speed limit. However a sensible check on the map before departure can remove the worst of these adventures |
|
Back to top |
|
 |
Kremmen Pocket GPS Verifier


Joined: Mar 03, 2006 Posts: 7223 Location: Reading
|
Posted: Wed Jan 24, 2018 12:06 pm Post subject: |
|
|
I think they are all trying to be too clever then.
Motorway = 70
Dual Carriageway = 60
A road = 50
B road = 30
Unclassified = 20
With the option to adjust each
or something like that, that's how MapPoint does it's calculations and it works. _________________ DashCam:
Viofo A119 V3 |
|
Back to top |
|
 |
MaFt Pocket GPS Staff


Joined: Aug 31, 2005 Posts: 15388 Location: Bradford, West Yorkshire
|
Posted: Wed Jan 24, 2018 2:01 pm Post subject: |
|
|
I live in Yorkshire. There are plenty of country roads where 60 is feasible. |
|
Back to top |
|
 |
M8TJT The Other Tired Old Man


Joined: Apr 04, 2006 Posts: 10118 Location: Bexhill, South Sussex, UK
|
Posted: Wed Jan 24, 2018 3:11 pm Post subject: |
|
|
MaFt wrote: | I live in Yorkshire. There are plenty of country roads where 60 is feasible. | But that's not the problem.  |
|
Back to top |
|
 |
arfurdent Regular Visitor
![]()
Joined: Mar 05, 2006 Posts: 116
|
Posted: Wed Jan 24, 2018 8:24 pm Post subject: |
|
|
MaFt wrote: | I live in Yorkshire. There are plenty of country roads where 60 is feasible. |
...and the sheep are very frightened |
|
Back to top |
|
 |
dales Frequent Visitor

Joined: May 04, 2008 Posts: 755 Location: Knaresborough, North Yorkshire.
|
Posted: Wed Jan 24, 2018 10:52 pm Post subject: |
|
|
This is Yorkshire...
...not Wales ! _________________ nuvi 2599LMT-D, oregon 700, basecamp, memory-map. |
|
Back to top |
|
 |
layingback Regular Visitor

Joined: Feb 12, 2009 Posts: 124
|
Posted: Thu Jan 25, 2018 11:13 am Post subject: |
|
|
Kremmen wrote: | I think they are all trying to be too clever then.
Motorway = 70
Dual Carriageway = 60
A road = 50
B road = 30
Unclassified = 20
With the option to adjust each
or something like that, that's how MapPoint does it's calculations and it works. |
I believe you will find the issue is related to road classification - grade if you like. Navtech-based maps (ie not Tomtom, Mappoint or Google) seem to have too few classes of road to provide distinction between various minor roads. The road classification would normally differentiate between routes first - with rated speed being used when both routes are equal in road classification.
Arguably TomTom is short a few classes for EU mapping, stemming from its USA origins where there are relatively few. But Navtech maps either don't have anywhere near enough, or they are mis-applied, or both.
In the Spanish countryside I see the same issue - eg routed off a new road onto a single track of 1km with a right and 2 left turns to 'avoid' a shorter largely straight road with short 30kph stretch in the middle. Could only do 30kmh max on their 'faster' road! Hence I have to have a 5" TomTom display sitting above an idle built-in 8" Navtech-based onboard nav!  |
|
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 |
|
 |
|