3790 navigation seems strange

alan_sh · Posted: Mon Jul 19, 2010 12:27 pm Post subject: 3790 navigation seems strange

I like to have my routes displayed even if I know where I am going so I can check arrival time, distance etc.

So, I have a route from Rochdale to Rolls Royce at Derby. TomTom 730 and my Garmin 550 route me down the M6 and along the A50 - which is what I want to do.

My new 3790 wants to take me over the back roads to Ashbourne. Which is a terrible road for a car. I have tried turning off all the options in Nuroutes, but I can't get it to route me down the M6 without putting in an internediate point.

So, anyone got any ideas how this works in the new thing. I have NOT set anything to avoid motorways (only U-turns).

cheers

Alan

haven_brian · Occasional Visitor Joined: May 02, 2007 Posts: 1

If it's any consolation, I find the same thing on my new 1690. Some of the route choices are bizarre and I kept wondering if it was diverting because it knew something about traffic ... but no I think it just has wildly optimistic views about how fast you can go on small country roads or motorway alternatives.

Recent worst case in Germany had me turn OFF a perfectly serviceable autobahn to go cross country to Munich airport. I had a bit of time spare so I decided to test it. It wound up taking 40 minutes longer than the device itself predicted!

Similar case, from Heathrow towards the M1, had me go PAST the M25 on-ramp and along the old roads to connect to M25 eventually at J19 ?!?!

Does anybody else find this in the latest models??

BigPerk · Posted: Wed Jul 21, 2010 10:26 am Post subject:

I'm quite puzzled. This was precisely the problem why I had to eventually move to a different make of satnav a couple of years ago, even though I like Garmin in many ways. So I'm very interested that it still seems not to have improved particularly. But there doesn't seem to be much said in the forum about routing issues, which I would have thought would apply widely across the range.
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David
(Navigon 70 Live, Nuvi 360)

p-brain · Occasional Visitor Joined: Jun 17, 2008 Posts: 30

I can also confirm rather odd choices of route on my 3790T. I have never previously used a satnav much, so can't really compare.

There are occasions when the 3790t routes me what would be both - longer in distance, and longer in time. With regards to time...these should be obvious, ie it routes me through a town rather than down a B road that would both be shorter in distance and shorter in time.

mikealder · Posted: Fri Jul 23, 2010 8:42 pm Post subject:

A simple rule applies here, if you know better simply ignore the device and carry on along your own route, this applies to all devices irrespective of make or model.

Whether the 3790T is better/ worse than other devices at producing strange routes can only really be checked out with multiple devices in the car at the same time which isn't something most people have the option or availability of hardware to actually compare units.

Having seen reviews in certain publications covering comparisons between the 3970T and some other high end devices I think its time to wait for the TomTom Go-1000 and run a head to head between the as yet to be released TomTom and the Garmin 3970T, sadly it looks like this won't be possible until September.

After a week of use the 3970T has produced a couple of routes that I simply ignored due to local knowledge, but I can't say I have seen it take A or B roads in preference to the motorway as Alan describes but its early days as yet and I have yet to venture out of Lancashire with it (planned for in the morning).

My initial impression is thats its a very good device, the screen quality is second to none in terms of visibility, contrast and resolution, reflections are present as you often find with capacitive touch screens but they are lower than seen with an iPhone which is a major plus point.

The use of the accelerometer coupled to both the Eco routes indicator and the view of the car is a real first, most interesting when "off the map" i.e driving on a road not covered by the map (an air base) and seeing the car slew sideways on the screen while driving around corners is a new one on me, but very effective in use - Mike

p-brain · Occasional Visitor Joined: Jun 17, 2008 Posts: 30

Yes, of course one can ignore the suggested routes if local knowledge prevails....but I want to be confident that when I tacke a journey I don't have too much prior knowledge about, that the 3790t will take me the 'best possible route'.

This is why I would very much like to be able to review (or create) routes on a PC prior to my journey.

I know all to well that if one relies on a Sat Nav 100% without any idea of what might be a sensible, or not so sensible route, you can end up driving for longer than necessary, or encounter unnecessary delays.

Don't get me worng, I really like my new toy...I just need some confidence that the nuvi will take me on sensible routes when I have less idea of where I am going (I have not tested this yet as I have only driven on routes I know well so far)

alan_sh · Posted: Fri Jul 23, 2010 9:15 pm Post subject:

Well, I had another interesting effect. Driving North up the M6 tonight. I had a route planned to home. As I joined the M6 Toll road, there are three lanes, - two to the left together and one which goes by itself to join the real M6 a tad earlier. The Garmin zoomed in as I was approaching the slip ramp on - I was in the right hand lane of the two together - and then keep zooming in until it could go no further. It then froze up. Solid.

I waited for a couple of minutes and then clicked the on/off button. It switched off. Clicked again and it switched on and carried on working as if nothing had happened.

Also, the traffic signal was rubbish. Over a 240 mile journey I probably had about 40 miles of real traffic signal. The rest of the time it either didn't display any traffic button at all or, if you pressed it, it just said "poor reception for the last 'x' minutes". Given that I was going up the M40/M42/M6 on a Friday night, knowing where the accidents and holdups were would have been nice!!

It may well go back if this keeps on. As Mike says, it's a lovely device, but it is still in beta for the firmware.

Alan

jdgwinnell · Posted: Sat Jul 24, 2010 10:09 am Post subject:

I think they must have re-written the routing software for the 3790 ... and got it wrong. Not only is it impossible to send routes from a PC (reports suggest that this is an issue they are finding it very difficult to resolve) but the on-unit routing possibilities are incredibly limited. Unlike all other routing Garmins I have used, there is no facility to insert a waypoint into a route - it will only add one at the end, so you have to get your intermediate via points in the right order when entering them. The 'optimise order' option is only available if there are four or more waypoints/favourites in your route, and even then it ignores the last one so it can construct a route that has you returning to an intermediate point as your destination if you entered it last. 'Optimised'! [hollow laugh] The only way to correct this is to delete your destination from the list and add it again, when it becomes the end point.

This software is barely in beta - more like alpha. Did anyone test it before it was released?
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J D Gwinnell
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nuvi 3598LMT-D
Montana 650, Oregon 650

travisb · Posted: Thu Apr 07, 2011 9:10 pm Post subject:

Sorry to drag this up again, but I've been experiencing similar hassles on my 1690. Some of the choices it makes on routes I do regularly are baffling. Minor roads instead of main roads, even for the shortest of distances. This is irritable but fine as I just ignore it, but on a route I didn't know, this could be a real pain.

The national press love a 'satnav navigated car off cliff' story, but the satnav companies do themselves no favours when their routing can be so bizarre.

Garmin especially, given their reputation in other markets should know better.
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LG G4, Google Nexus 9, Garmin Oregon 600T

Wazza_G · Posted: Fri Apr 08, 2011 4:11 pm Post subject:

It does it to me, if I ask it to take me to Belgium via the Chunnel, it tells me to turn right out of my road & do a U-turn to go past my road & go towards Dorking & the A25, this is because someone got it wrong about the information about leaving our road. Rolling Eyes

Then again sometimes it tells me to go through some of the country lanes to Guildford & on to the A3 and M25.

As said I ignore it initially because I know better & then let it continue, the only real reason I have it is because if there's an incident, I can get it to find a way around the problem.
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G300PBV · Posted: Sat May 21, 2011 11:17 am Post subject:

The wonky route problem has been addressed on here a few times over the last year or so.

AFAIK the route calculation software assumes that you will travel at the fastest speed permissible for whichever road you are travelling on. I always have my device set to Fastest Speed and so this becomes a problem when the unit finds an unrestricted road which it correctly assumes is National Speed Limit, often 60mph. What the unit doesn't know is that these roads are often single-track where you are lucky if you can achieve 20mph. This used to happen a lot on previous models when, in North Wales, I would be turned off a perfectly good A road only to clatter along some farm track for a mile and then rejoin the A road, except now I have to turn right.

Microsoft had a route planner program for the PC (Autoroute?) with a useful setting on it. You could set your preferred maximum speed limit for each type of road. So, if you wanted you could set 60mph for motorways and 20mph on single track roads. The software would then use these figures in it's calculations.

Why Garmin (and others) cannot implement this simple feature is beyond me. It would avoid many of the issues we experience regarding puzzling routes, but only for Fastest Speed.

BigPerk · Posted: Sat May 21, 2011 1:03 pm Post subject:

Yes, IIRC either Garmin or TomTom used to provide the option to set your own speed limits for the road types if you wanted to, but then dropped it. Seemed a shame.

But while max speed presumably accounts for many of the routing problems, I'm not sure it's the whole story. When I had some of my diversions they sometimes suddenly changed routing instructions and turned me off a dual-carriageway A road in mid-route taking me for miles and miles over country roads - but no dodgy traffic reports. Once I even had a journey where the route out was fine, but the return would not use A roads at all; even if I tried to force it by getting on to a London-bound A road, it kept trying to take me off again. I wondered if my settings had been changed in error 'under the counter', but they still seemed to be fine.

My backup paper maps were a godsend - I never go without them now!

But I agree - obviously there will be some quirkyness on occasions with any unit (but probably still better than getting hopelessly lost), but it is extremely discouraging if you can't rely on your satnav for the basics. It certainly knocked my confidence big time.
_________________
David
(Navigon 70 Live, Nuvi 360)

timlofts · Occasional Visitor Joined: Aug 07, 2006 Posts: 16

I don't think the 3790 has any uniquness regarding routes, all Sat Navs can produce "Sat Nav Specific Routes", and I still think it's neccessary to have proper map knowledge before setting off on a long route.

Last year I was in Cornwall using Sat Nav routes, that were opposite to what the road signs were telling me, and evntually I came to the conclusion that the best thing to do was open the window, unclip the sat nav, and throw it as far as possible! There was no way my car was going to fit down some of those tiny Cornish fishing village streets. Exclamation

Andy_P · Posted: Fri May 27, 2011 10:04 pm Post subject:

kraftykarl · Occasional Visitor Joined: Dec 08, 2006 Posts: 8

I work as a mini-cab driver within Greater London and for years I was a fan of Garmin Satnavs (I still have a 60csx for hiking).

Last year I bought a Garmin 1690 because of the connected services. Greater London has constant traffic issues so any system that helps you to avoid traffic hotspots is a major advantage. At first I was thrilled at having the live traffic information, being able to see where the problems were on my Satnav before I left on a journey.

Once I started using it and following it's suggested routes for avoiding incidents however the shortfalls of the Garmin routing became obvious. It would route me off of motorways to save 6 or 7 minutes in the rush hour (what an outdated term that is) but the alternative route would be slower and more hassle than remaining on the M25. I found myself constantly reviewing it's suggested routes and using my own knowledge to decide whether to, or how to avoid the delays. Of course this might be considered a good practise anyway but it crossed my mind that my Garmin was actually little more than a digital map with additional information while I was using it in this manner.

Last year I obtained an Iphone 4 and purchased Tomtoms Satnav software and subscribed to their HD traffic service. The difference in the quality of the routes created is totally superior around Greater London and I only occasionally find myself over-riding it's route suggestions. I do miss the advantages of having a stand alone Satnav with a nice clear, large display but as a professional driver around London it's the routing that is the important thing for me. A cheap windscreen suction mount and a blue-tooth ear piece mean that I can use the Iphone for navigation as well as phone calls while driving.

Outside of London I found the Garmin routing to be totally adequate but when it's put to the tough test of routing through busy Greater London in traffic the weaknesses in Garmins routing become obvious.

IMO Garmin really dropped the ball and didn't respond either quickly or effectively enough to Tomtom's IQ Routing and HD traffic service. It's a shame as I much prefer the build quality of Garmin's units but I will place functionality over attractiveness any day.

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