BMW R1200RT/R1250RT Forum

This is driving us nuts :beee:  I just don't get the algorithm used by Garmin on deciding routes.
Couple of examples come to mind.
Last June we were on tour in Europe and needed to get from Eschdorf in Luxemburg to our next hotel in Alken on the Moselle river in Germany. First half of the route to Bitburg was great, then it all went to pot.
Looking in the map book it looked a nice easy route and the Sat Nav showed a journey of an hour.
It was hot (30+) we were tired so I changed the setting to fastest route.
An hour later, the sat nav was saying journey time of 2 hours from where we were, and we had been up and down single track roads with VERY tight hairpins every hundred yards or so and I was ketting kind of pissed off and my wife was saying she was sick and tired of all the hairpins and just wanted to get to the hotel.
I tried changing the setting to shortest route, but when scrolling through the preview of the route, good old garmin was STILL planing on taking us on single track hairpin infested  roads.
We had no idea where we where, but luckily we came across a tiny bar in an unnamed village where I was able to ask in my poor German "Where the hell are  we?"
Having had our location pointed out on a map, we saw an autobahn [size=2px]just a few miles away that would get us close to our destination. At this point I [/size]foolishly thought that he sat nav would be OK once we came off the autobahn and lead us straight to the hotel.
[size=2px]Guess what? Yep, no single track roads but a huge loop away from the hotel before swinging back and crossing the river to Alken. The one hour journey had turned into close to 4 Hours!!!!! [/size]
[size=2px]Boy did the beer taste good when we arrived.[/size] :beer:
The next day we had to go back to Bitburg to meet up with my Son-in-Law and daughter, so I followed the road signs, had a fantastic ride on roads perfect for an RT and it took only just over an hour.


That was not the only occasion on that trip that the sat nav tried to take us on crazy routes, but having just come back from touring in the Dordogne, I am ready to bin the Garmin and no matter what settings I used, it insisted on trying to take us on tiny farm tracks at every opportunity. God knows why as the roads it was trying to take us away from where biking heaven with bend after bend with fantastic road surface. being out of season the roads were quite quiet as well.


Thinking about it, if you put in shortest route, the algorithm will obviously try to cut corners but why does it try to use the crazy roads if you put in fastest route?
Our theory is that the programing looks at the speed limits on the roads, so if the single track hairpin infested road has a speed limit (hah!) of 90kph and the main road's is 70kph, the algorithm will say use the road with the highest speed limit as that is obviously going to get you to the destination quicker >:(
So, is it just my Garmin, or do others have the same issues?
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Been there done that! >:(
I now never rely on a satnav to get me where I want to go. I look at a map, plan a route so that I know where I should be going. I then use the satnav but ignore it if it tries to send me on a road that I just don't like the look of (and it will!). Just let it keep recalculating until it takes me where I want to go.
It did it to me in Greece trying to send me off into the wilderness on a goat track. Fortunately I had an idea of the direction I wanted and sure enough half a mile later it rerouted onto a decent road.
Satnav's are great for taking you to a pinpoint destination but keep a map in your tank bag!

You do not tell us what model Garmin you have.

My first piece of advice (having learnt from others) is to take the SatNav out of motorcycle mode when entering destinations on the fly. It calculates some very weird routes in this mode (my Navigator V has never been out of Car mode). Nor do I ever use motorcycle mode when planning routes in advance in Basecamp. Make sure that you don't have a "curvy roads" option set in the route preferences. 
You could experiment with this feature while seated comfortably on your sofa and compare the planned routes.
I can honestly say that none of my Garmin's has every taken me on what I would consider to be a completely stupid route - odd maybe, but not stupid.

Sometimes I don't think the Garmin is brilliant at distinguishing a poor road with grass growing in the middle from a "normal" surface. When this happens I just ride past the suspicious turning and the unit calculates a less stressful path.

I am sure others will chime in shortly with their experiences.


Totally agree with having a map in the tank-bag!

Nav 5 from haywards heath to Portsmouth fastest or shortest route is via guildford. I've just been an idiot for years going all along A272 or A27. Thanks BMW and Garmin for showing me error of my ways.

BoB21 wrote: Nav 5 from haywards heath to Portsmouth fastest or shortest route is via guildford. I've just been an idiot for years going all along A272 or A27. Thanks BMW and Garmin for showing me error of my ways.

I have just entered a route into my Nav 5 -  Haywards Heath to Poole Ferry. It proposes A272 and A27 using fastest time, Car mode.  So I had a play around with different route settings and I couldn't make it suggest a route via Guildford.

Ironically had old cheap car nav from garmin that did the same thing

beemerboy9 wrote: You do not tell us what model Garmin you have.

My first piece of advice (having learnt from others) is to take the SatNav out of motorcycle mode when entering destinations on the fly. It calculates some very weird routes in this mode (my Navigator V has never been out of Car mode). Nor do I ever use motorcycle mode when planning routes in advance in Basecamp. Make sure that you don't have a "curvy roads" option set in the route preferences. 

Sometimes I don't think the Garmin is brilliant at distinguishing a poor road with grass growing in the middle from a "normal" surface. When this happens I just ride past the suspicious turning and the unit calculates a less stressful path.
.

It's a  Zumo 660, and I have tried using it in car mode with exactly the same results!
There is no "curvy roads" option on mine, though that was a good suggestion.
We have found that using a map book and having a list of towns and ignoring the ridiculous suggestions from the sat nav works best.
I was just wondering if mine was a dodgy version!

My 595LM was doing exactly the same thing, last time I used it ( Leicester to Hemel avoiding motorways ). I even had my phone running Google maps, for comparison and a few times they gave turns in the opposite direction.

I hadn't thought to try 'Car' mode, which I will do next time.

Had a 660 for 5 years then moved to a Nav V, can't say I have had any issues with route selection or routes. I do however review the route and if it does try to take me off the main route, I ignore it, like any sensible person would. So its more a back up to the route I already have in my head. The only reason I started to use a sat nav was my eyes wouldn't allow me to read a map on the tank anymore

+1 what Casbar said.  Always be suspicious when it sends you off a main road an up a goat track as it could well be cutting the corner.  I've watched the ETA going out when on small roads and pressing on a bit.  As mentioned above, in the absence of speed limits, Garmin seems to think that the speed limit is also your average.  Must admit I always review the route on Basecamp before going anywhere new.  The other watch out is to make sure you have not dropped in a random shaping point in the wrong place as this can send you out into the wilds just to make a U turn and come back.  Don't ask me how I know......

Garmin's okay, but you need to get used to its oddities.  As a general rule I think the hardware is great but the software is less than great (beingcharitable)

Set mine to avoid roundabouts somehow, made all journeys interesting until I found avoidances in the set up menu.

I have lost count of how many years I have been using Garmin units for so I guess I have just become accustomed to this particular 'feature'. It's a common topic on family holidays when we know the route will take us down at least one 'detour'. As has been stated above, the answer is to actually look at the route first and do some planning rather than just entering a post code and waiting to see what happens.


I have written it off to the fact that with the sheer volume of mapping information Garmin have to process there is no way that they can realistically know (or deal with) the fact that one 60 mph road 'unclassified' road is not the same as another. The route calculation algorithm just sees two roads, both with national speed limit, one of which is a mile or so shorter than the other. It makes what it considers to be the 'fastest' route based on distance.


A few weeks ago we were on holiday in Wales, at a small cottage deep in a valley. Most of the places we wanted to visit were South of us down narrow winding roads, many of them of the 'six-foot-six with passing places' variety. After one such trip I quickly worked out that there was a major A road running North/South just a few miles to the East. Getting to it meant heading in the wrong direction but once reached the journey was much faster, and a lot less hard work.


One day they will start to incorporate some sort of AI into navigation algorithms, but until then I think we have to accept their limitations.

I've been using a 660 and recently got a Nav V, and before that a car version. The car only went a bit bonkers on two occasions, first time was when leaving the covered car park after entering the destination coming out of Geneva Airport with no signal it went a bit off and we accidentally entered a "via destination" The second was going to Geneva with a minibus over the mountain passes, the first of which was closed. Have to say on the bike it has been pretty good so far, been down to Lucca in Italy and nailed the final destination by the co-ordinates and gone off route a few times just for fun and it sorts itself out. There are a few options for routes and it seems to depend on what you set these to as to the route it works out, not just the fastest or shortest or scenic.
I agree with others, usually have a look at the general direction on a map before setting off and road signs in case it does lose the plot.

I've given up on BaseCamp some time ago. I use Google Maps to design my route, then import the .gpx file into basecamp, then download it to the Nav V. As long as Basecamp and Nav V have same settings (avoidances, etc) it will faithfully reproduce the route when it recalculates on the Nav V.  Of course this doesn't work very well if you're on the bike. You need a laptop to do it.