sat navs for motor homes

[GJH]

RogerGW - 2009-06-08 6:04 PM

 

GJH - 2009-06-08 5:25 PM

....I assume that using the motorways would have saved us a few seconds so worked out to be the fastest route.

 

It sounds to me as though it did exactly what you asked of it. What's "naff" about that?

 

Roger

Every other time we've done the journey - including going to Stratford on Thursday - it's taken us along the A46 and M69.

 

I haven't updated the mapping for a couple of years and don't subscribe to any real time routing package so why should it do anything different? Given the same data it should have come up with the same result as before. Not to do so is certainly strange, if not naff :-)

 

Graham

[GJH]

Mel B - 2009-06-08 7:21 PM

I tend to try 2 comparing routes - first I do the fastest and then do a comparison with an alternative to this, or even the shortest, in some instances there is very little time difference, maybe a few minutes if that, but the extra mileage can be quite a lot. At least then you can choose which you wish to follow.

I've tried that from time to time, Mel. I've found, though, that it sometimes includes side roads and narrow lanes which happen to be a bit shorter but may well be difficult to navigate, especially in a large vehicle.

 

These days I tend to ask the TT for a route some days before we travel and then compare what it gives against a road atlas.

 

Graham

[RogerGW]

GJH - 2009-06-08 7:24 PM

 

Every other time we've done the journey - including going to Stratford on Thursday - it's taken us along the A46 and M69.

 

So you only told us half the story, if that. 8-)

 

Roger

[Guest Tracker]

When will people realise that a Sat Nav, clever that it is, is only another navigation AID and just like a map be it computerised or paper it needs to be used thoughtfully.

 

I too often key in a route when we are on a known route and it does throw up some interesting if illogical routes which, if we are in the mood, we sometimes follow.

 

What this has achieved is doubtful, other than to lead me to distrust the Sat Nav, so for very long journeys so we tend to break it into smaller chunks by using the key towns along a paper map planned basic route and if it wants me to turn off when I disagree I simply do not turn and it soon reroutes itself to follow my chosen route.

 

If it asks you to turn down a narrow road - or the road gets narrow after you turn why not just stop and either check on your map - you do carry a map - don't you - and then judge whether to go on or go back. After all one of the main joys of a Sat Nav is that you ALWAYS know exactly where you are because it shows you.

 

It really is not that complicated!

 

 

[Brian Kirby]

The original question concerned sat navs for motorhomes.  To be really useful it would have to have an inbuilt vehicle size selector that would, at minimum, have to cater for vehicles weighing more, or less, than 3.5 Tonnes.  It would also need to have some means to enter height, and ideally width.  A few sat nav devices, aimed mainly at trucks, have these facilities.

However, unless the road mapping used includes all information on width, height, and weight restrictions on all roads, there is no information for the machine to use in selecting routes, and the vehicle parameters will not be usable.  The above restrictions are being incorporated into the most recent versions of the map data for both the main providers of electronic mapping.  However, at present, to the best of my knowledge, the information is incomplete even for UK, and is patchy outside UK.  This information is also, at present, an extra cost overlay to the standard maps, which is part of the reason the truck oriented systems are more expensive.  TomTom have a system they sell to fleet operators but say they will not (yet) sell this to the public.

So you can enter the vehicle data to some sat navs, which then will use the additional mapping data to avoid height, width, or weight restrictions - where these have been mapped.  However, that is the snag.  Not all such restrictions are mapped to the extent you can avoid looking out for them, and even where mapped, you will only avoid the legally binding restrictions.

I understand that current electronic mapping does not take account of road widths generally, so your wider than average motorhome may well be directed, quite legally, down a rural lane that is narrower than the motorhome, because no-one has placed a width restriction on that road.

Final drawback, applying to all sat navs so far as I know, is the process by which they calculate the quickest route.  This is far from the level of sophistication that is really required, and seems to be based upon the national speed limits applicable.  Thus the unit may choose a shorter route comprising narrow twisting lanes through which few would drive faster than, say, 40 MPH, in preference to a more circuitous route along good main roads on which one can reasonably travel at 60 MPH.  The lanes look quicker to the unit because it "thinks" you would drive at the same speed down both routes.  In fact, in many cases, the longer route will prove quicker because you can, actually, drive faster, but the poor little sat nav knows nothing of this. 

This kind of flawed logic seems also to apply in the case of "shortcuts" across long bends, where an alternative road cuts off the bend by a few yards.  One end or the other of the shortcut, you will have to cross the opposing traffic stream, so will probably have to wait for a gap in the traffic to do so.  Probable result, you get delayed and the shortcut is a complete waste of time.  What is traffic to a sat nav?  Hmmmmm!

For all these reasons, and more, you need to use maps for planning, and for monitoring progress en route.  One thing some of them is good at, is lane guidance at complex motorway junctions, but that apart, you don't really need a sat nav to navigate motorways, just the ability to read signs!  The technology, and the map data, are improving all the time, but the totally reliable sat nav even for cars, leave alone motorhomes, is some way into the future yet.  If you have a motorbike, you're well catered for because so few restrictions apply, otherwise they are still a great tool - provided they are used with caution.

[GJH]

Thank you Brian.

 

As so often happens, summarised very well.

 

Graham

[Tomo3090]

Just used our TomTom 1 Europe through France Spain and Italy and it worked fine for 99% of the time. It sorted out routes and journey times quite accurately and got us through some complex areas and to places that map reading wouldn't have. It also stopped us having almighty rows about what and where we should have turned!

 

But for that 1% it did get threatened with going through the window!

 

But at all times you do need to remember it's just the navigator NOT the pilot! ;-)

[Guest JudgeMental]

lennyhb - 2009-06-06 2:08 PM

 

Sat nav is fine for finding your final destination & works tolerably in the UK but is naff at route planning across the continent.

A lot of the early sat nav’s allowed route planning on a PC that could be downloaded to the unit I don’t think any modern unit supports this.

 

 

 

Garmin still offer this and I have been using it since 2000. You are correct in that with the 600 series Nuvi's this facility disappeared for a while, but is back with the 700 series and has always been available from a few other models......

 

You need to install a copy of Mapsource (DVD) on your PC/laptop and then you can plan away in comfort and download your routes, waypoints etc at leisure.....

 

 

[Brian Kirby]

JudgeMental - 2009-06-09 12:20 PM

lennyhb - 2009-06-06 2:08 PM Sat nav is fine for finding your final destination & works tolerably in the UK but is naff at route planning across the continent. A lot of the early sat nav’s allowed route planning on a PC that could be downloaded to the unit I don’t think any modern unit supports this.

Garmin still offer this and I have been using it since 2000. You are correct in that with the 600 series Nuvi's this facility disappeared for a while, but is back with the 700 series and has always been available from a few other models...... You need to install a copy of Mapsource (DVD) on your PC/laptop and then you can plan away in comfort and download your routes, waypoints etc at leisure.....

But - do check very carefully what you are actually buying.  I bought a Nuvi 700  this time last year, and the CD with MapSource was not included - even though the packaging stated that MapSource was included.  Garmin wouldn't budge and said they no longer included the CD because, as the device now had much greater memory capacity, all of Europe was now pre-loaded, so one no longer needed MapSource to load the various country maps.  Eventually solved with some assistance from Garmin and Judgemental, and I have now taken out the lifetime updates subscription which includes Map Install, which in turn can be upgraded free to MapSource.  So, all maps are kept up to date and MapSource is available for use as and when.

One further note on MapSource.  It is a useful tool and will calculate routes from A to B on the PC.  If you don't like the roads MapSource selects, you can pull the route onto different roads and it will insert waypoints.  The modified route can then be transferred to the Garmin device, and can be called up so that it is used for navigation.  Problem?  Of course there is.  Sometimes the modified route from MapSource transfers as a cat's cradle of interwoven waypoints that would have you driving backwards and forwards in ever decreasing circles. It is presently unclear what causes this glitch, but it didn't happen before I upgraded the maps to the 2009 version!  Second problem is that once you've set up and transferred you route from MapSource, the device does not use the same routing logic when it follows it, and still takes loony shortcuts etc between waypoints where MapSource took an acceptably sane route.  Garmin say this tendency is inevitable, because the PC has far greater memory and calculating power than the device - which seems reasonable - but makes the facility to plan on the computer and transfer to the device a bit of a lottery.

Moral - just keep those maps handy while travelling, watch closely where it is trying to send you, and reject all suspect routes.  I have collected quite a few horror stories from others I have met on this trip who have followed their sat navs blind.  Be careful out there!!  :-)