Garmin 510 - ridiculous routings

I bought my wife a Garmin 510 (with Trafficmaster) just before
Christmas. We've checked for updated maps - ours are seemingly the latest.

In many areas, the unit comes up with very sensible results, but in two,
simple, rural areas that we know well, it produces ludicrous routes - so
bad that I wouldn't trust it in an area that I didn't know (which, of
course, is the whole point of the thing).

ERROR 1: Cumbria

Heading for Ambleside from Kendal on the direct A591, the unit wanted to
send us northwards at the village of Ings. It was really keen on doing
this - even after ignoring the first right turn, it recalculated and
tried to get us to take the next right.

The snag is that there are only two conceivable routes between Ings and
Ambleside: the direct A591, or a very long detour via the top of the
Kirkstone Pass (at an altitude of nearly 1500 feet). This is a
ridiculous detour at any time except when the main road is seriously
jammed - which happens for an hour or two on peak summer days only.

Ignoring the instructions, the unit quite happily tracked our
(traffic-free) progress along the A591, so it isn't as if it didn't know
there was a direct route. What was it playing at?

ERROR 2: Derbyshire

Heading to Buxton from Ashbourne, there is a direct (and mostly very
straight) main road, the A515. The Garmin was rather keen that we went
via the village of Alstonefield, several miles off the main road. I like
Alstonefield very much, but not when trying to get from Ashbourne to
Buxton. The unit was so keen on the Alstonefield diversion that it was
urging diversions in that direction even as we approached the centre of
Buxton.

I am staggered at such bad results. Have we been incredibly unlucky in
finding two errors in our first few days of use - or is the Garmin
mapping (or routing algorithm) seriously dodgy?

John Geddes
Derbyshire

Basically all the sat nav units can produce some iffy results so it's
always best to do a quick inspection of a route before setting off
just to make sure there are no obvious detours, on the whole however
they do a good enough job although most people could probably think up
a better or similar route given the right maps and enough time --- but
it's this fiddling about with maps that we're trying to avoid and
sometimes you have to pay for the convenience with some routing
decisions made on bad data. I've been using satnavs for a long time
and they're not spot on but certainly good enough. The biggest
whoopsies are usually easy to spot.

--
Blast off and strike the evil Bydo empire!

On Mon, 7 Jan 2008 17:13:06 +0000, John Geddes wrote


I don't understand this at all. I have a Garmin 2610 and I tried both your
routes on my unit (using the 'faster route' option). In both cases it gave
the obvious route that you have suggested i.e. Kendal to Ambleside via the
A591; Ashbourne to Buxton on the A515.

I imagine Garmin use the same routing algorithm on all their units so as I
say I can't explain your results. Are you sure you have not inadvertently set
some preference or avoidance on your unit? On my 2610 for example you can set
a preference to avoid main roads which might well produce your results.

--
Mike Lane (UK North Yorkshire)
To contact me replace invalid with mike underscore lane

latest.
=20
=20
=20
=20
=20
I have had similar bad experiences with a Nuvi 670!

I have had a TomTom Go910 for over a year and never had any real
problems (I also drive a Truck).
A few months ago I decided to try the Nuvi 670 and it turned out to be
a big mistake.

I tried it for 10 days with routes I have done many times and 1 route
in Falkirk gave me absolutely ridiculous results.
Basically the are 2 main routes from this location in Falkirk to
Carlisle, one takes you a couple of miles to the M9 and then M876,
M80,A80,M73 and then to the M74 South.
This is the route most, including the TomTom would default to.
However instead of turning Left at this roundabout and heading for the
M9, I turn right, which takes me through a small town (Camelon) and
joins the M876 South. This route is quicker and misses out the M9.

Now, when I take the different route with the TomTom, within a few
yards it recalculates and "respects" my decision to take the alternate
route and then gives me the correct instructions for the new route.

Now the same route taken with the Nuvi 670 produces totally
unacceptable results.
It refuses to "respect" my decision to take an alternate route and
insists at "EVERY" possible side street, to turn around, even
navigating me onto housing estates!. (I even had it set to "Truck"
mode)!.

I had traveled to within half a mile of the M876 before it would
recalculate the correct route!.

The Nuvi gave similar results on several other routes, so needless to
say, I got rid of it quickly!.

I would doubt if all the Garmins behave this way but it makes me
wonder if this is not a problem with the Nuvi range?.

Good luck...

=DFarney

I tried simulating both these journeys on my StreetPilot C510 and my Nüvi
310. No matter what Avoidances/Preferences I set, I couldn't get it to
reproduce your routes - both units came up with the expected routing.

However, I also tried it in Mapsource and couldn't STOP it picking your
routes?!? Mapsource has quite a lot of parameters you can mess with,
compared with the C510 ... and no doubt, I will eventually find the one
that's causing it (on the PC). However, when it comes to the C510, it's a
bit more perplexing.

I read a while ago, about these units 'learning your preferences' - and
dismissed it as an old wife's tale. However, I'm just wondering....
..no - surely not! - there's got to be a more rational explanation!

--
http://GeePeeEx.googlepages.com

GPX Editor for Garmin Automotive Units