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|T O P I C R E V I E W
||Posted - 06 nov. 2008 : 23:52:16
GUIDE - Working with programmed multi-point routes
Using pre-programmed routes with multiple stops is one of the more complex aspects of using a GPS and since this is something I had to figure out how to do on a nuvi 760 during the Scooter Cannonball 2008 across the United States, I thought I would share my experience in this guide. The original discussion is here and please excuse some repetition from that, and introductory info, as it makes it easier to understand the answers to the routing questions.
A Route with Checkpoints
The race followed a pre-determined route, with checkpoints, meaning that the scooter riders had to prove (via time-stamped photos or track logs) when they had arrived at each checkpoint on each day’s route, which mostly followed US 50 from San Francisco to Ocean City, MD. Everyone spent each night at the same location, so each day was its own race, counting toward the total. Sort of the Tour de France method, without the drugs [g].
I drove a support truck, so I was not required to follow the exact route, but in many cases chose to do so to provide a “sweep” function, looking for folks with breakdowns or other problems. I was using a nuvi 760, as was another of the support vehicles. The scooters were using mostly Zumos, but also an assortment of all kinds of GPSes, including nuvis, a StreetPilot, and Garmin’s Mobile X10.
Using the GMapToGPX plugin/java app
The official routes were created in Google maps and I used the excellent GMap to GPX web-based converter to get them into a format the 760 could read. They required a lot of editing. I used RoadTrip (now BaseCamp), the Mac equivalent of MapSource. This was very important, especially when it comes to answering gpspassion’s questions about recalculation, because proper placement of “shaping” points, vias and waypoints has a big influence on the outcome.
Editing the route
You want enough points to “force” the nuvi to conform to the pre-planned route, but you also want to be careful placing and naming them so you don’t get driven crazy by announcements of arriving at “GRTP-0071” or by that announcement overriding and masking an important turn. For example, if the next turn is at Main Street, placing a route point too close to that intersection would be bad. Better to insert the point (if one is needed to enforce the route) a mile or so back and label it “Main St. Next.”
The first big decision was how to organize the route files. The three choices were as follows. 1) One huge file from SF to MD: bad idea for a number of reasons that should be obvious. 2) One file for each day of the race: this is what most people did, but in my opinion it needlessly raised a lot of the recalc and arrival notice issues explained below. Its main advantages were eliminating the need to push buttons during the day (don’t forget, these guys were on scooters), and lack of confusion about which segment of which day was active. 3) One file for each segment, meaning that each file’s final destination was one of the checkpoints.
Day 6, segment 1, from Garden City to Greensburg, KS.
The plan was to follow the official route to each checkpoint (though I did opt not to in some cases). Above is an example of a segment from Day 6, which in its entirety went from Garden City KS to Fort Scott, KS, a distance of 364 miles. The first segment went from Garden City to a checkpoint in Greensburg, covering 94 miles. Note the two orange flag waypoints which show a dogleg in Dodge City to stay on Rt. 400. There were four segments in all on Day 6.
Here’s why I liked this approach: A smaller file imports faster and there was no problem putting the roughly 50 files needed (10 days times 4-5 checkpoints per day) into the 760 all at once from my computer. Then it was easy to delete the day’s segments each night and import the next day’s, all on the 760. I left my laptop at home. But I should have used better labeling. Calling them things like “Day 8 Segment Two” was dumb – after 3 days on the road I had no idea what day or segment it was and should have labeled them like this: “Cedar City to Bryce Canyon.”
Preventing recalc disasters
But the most important advantage was that it created a kind of firewall against bad recalculations. In other words, no matter what the 760 decided to do if I went off-route (or even if it merely thought I did), the “final” destination for each loaded route was the next checkpoint.
As a safety net I also created a Custom POI file of nothing but checkpoints. That way no matter how badly the nuvi got confused (or I did), I could cancel the route and navigate directly to the next checkpoint using the “fastest” route pref on my 760. A further safety net was a POI file of all the event motels, meaning I could also navigate directly to them.
The end of segment 1. Segment 2 (next route) starts where 1 ends.
OK, so how did this all work in the real world? Pretty well, but not flawlessly. It’s a little hard to tell how much to blame firmware 4.0 and how much is due to quirks of the 760 and its routing engine. It is possible to preview the “worst” of the recalculation problems using BaseCamp or MapSource (force them to recalc your route before transferring it to the GPS), but those programs use different preferences and avoidances than many Garmin models, so you may only be able to detect gross errors.
When you first import the route, it should be identical to what you mapped on your computer. In most cases it was, but one route file, for reasons I have not been able to discover, would load but not begin routing until/unless I changed a routing pref on the 760, forcing it to recalculate.
That’s the bad news. The good news is that for the most part, recalculations did not ruin the routes, sometimes inserting no changes, sometimes inserting small, insignificant ones. But several times it did cause problems with directions that varied too much from the assigned route.
The difficult part was guessing how to set prefs and avoidances to keep this process under control. “Shortest” seemed to produce the worst changes; “fastest” was OK, but bear in mind that we were far enough from major roads that routing to an interstate was often out of the question, so this wasn’t a proper test of prefs in that sense.
I ended up un-checking the U-turn avoidance because it made a big difference during recalcs. With it checked, the GPS would often try a wacky route (again we were in the boonies; avoiding U-turns was not a simple question of jogging right three times through a handy subdivision). Leaving it free to call for a U-turn alerted me that I had gone off-route as opposed to the 760 just losing its mind.
What happens if you go off-route?
Does it :
_a. recalculate the whole route and risk make you use different roads ?
_b. take you back to the next "waypoint" ?
It appears to sort of do “b.” It recalcs the whole route, but picks up where it left off and navigates to the next waypoint or trip point. If this results in a wacky, illogical route (rarely), you can delete the route and re-import it.
I don't know of any way to turn off recalc on the nuvi 760, or I would definitely have done it. The only times I had to "abandon" a route and then re-load it were 1) when the 760 wigged out (perhaps due to FW 4.0) and 2) when I had to backtrack to rescue a broken scooter.
Reloading the route works, but good planning with trip points, vias and shaping points (all ways of forcing the desired route in BaseCamp/MapSource) are also very effective when done in advance.
When you've reached a waypoint, any tolerance?
The 760 appears to treat every possible type of point in your pre-planned route the same way it deals with vias, so it announces arrival at all of them (see above for how this can be both good and bad). The computer software lets you set proximity alerts, but unless it’s a Custom POI in its own file, the 760 ignores this, unfortunately, so tolerance seems to be the same as for a via, meaning if you are way off it may try to make you backtrack to reach it.
Can you choose to jump to the next waypoint?
No, not unless you manually edit the route to eliminate the waypoint, which I did not try. But it will eventually give up and stop trying to send you back if you drive around one on purpose. Under 4.0 this function was too aggressive in the 760, compared to my 350 or 680, which will gracefully yield to my new route choices a lot more politely [g]. It behaves better under 4.2. This is partly why I created the Custom POI list of checkpoints as explained above.
I hope this is helpful and feel free to ask questions and continue the discussion in this forum topic.
|15 L A T E S T R E P L I E S (Newest First)
||Posted - 12 août 2013 : 17:32:08
Thanks for the kind words and the info.
On the zumo 660, if you turn off the GPS with a route active, that route remains active when you power up, with (I think) no changes and no options offered. I'm guessing your 765 recalcs the route when you choose Resume?
Also, on those occasions that a route does get munged by a recalc, I have found it is often not enough to Stop and re-activate because the new, recalculated version is what you'll get. Instead, I need to delete the route from active memory (using My Data) and reload it from my stored GPX files on my SD card.
However, that is a rare occurrence, made even more rare by use of the "ask me first" option the zumo offers under recalc preferences. Saying no displays the purple stripe and makes it easy to rejoin the route, at which point the voice directions resume and life is good.
||Posted - 12 août 2013 : 16:34:51
Dan this is a great guide. One topic you may choose to add is what happens if you TURN OFF your GPS during the route, for example at an unplanned rest stop, and then power it back on. We see the "RESUME CURRENT ROUTE" option, but in our recent rides we found a problem with this. In both my 765T and friend's Zumo 550 we have found that the results differ between choosing to RESUME, vs STOPping the route and reloading it. Stopping and reloading the route will put us back on the planned route to the next viapoint, while resuming will generally route us in ways we would not expect.
||Posted - 23 févr. 2012 : 11:06:00
Thanks Dan. I went for the 2595 because it scored the same features on the "Compare" function list as the Zumo but had the 5" screen that I must have.
It seems to me that one of the big problems here is that you cannot get accurate information from the Garmin advisers. I suspect that what happens is that the 'phone support people answer questions based partly on the info on the Garmin website; thus if that gen is incomplete or wrong (as I have found) you will receive bad advice. I was told yesterday, categorically, that NO Garmin units are compatible with Mapsource, yet you Dan and sussamb have units that do work with it.
Dan, I believe you're right to say the unit uses the "Trip Planner" function to handle journeys uploaded via Basecamp. Certainly that's where you have to look to find the uploaded file in the unit when you come to use it - you go "Apps" -> "Trip Planner" to get to it. You can then scan the list of way/viapoints and compare it with the Route Properties in Basecamp which is useful because you can detect any that have been missed out.
In this latter aspect, scrutiny of the file in Basecamp reveals that on a sample Route comprising 24 waypoints of which only 22 made it into the 2595LMT the missing two points were both located at junctions. When I edited the Route in Basecamp to move each of those two points onto a single stretch of road, then reloaded the data into the 2595LMT, all the 24 points were transferred.
This is at least a potential improvement for me. It still leaves the risk of the device choosing a stupid path to get between one point and the next but I guess avoiding that will be down to careful composition and point placement. I'd still rather have a breadcrumb trail and if Garmin have the technology to do this in the handheld range I don't see why they don't do it in the satnavs; not enough consumer demand, I guess!
||Posted - 23 févr. 2012 : 08:45:12
Dan, it was probably the 2495, there isn't a 1495 . In fact the 14xx series (Pedro, I live in UK and have one) accepts 'routes' from both Mapsource and Basecamp, I used to use Mapsource but have now moved to Basecamp. I've heard of the problems with Trip Planner on the later nuvis, which is why I'm hanging on to my 1490 as long as possible
||Posted - 23 févr. 2012 : 00:18:40
Welcome to the forum. I'm not up to speed on the 2595, but I suspect it uses the new Trip Planner function instead of routes, and the unit I road tested that used Trip Planner (I think it was a 1495) was a nightmare for the reasons you describe. This is why I bought a zumo 660. It accepts routes from BaseCamp (or MapSource, though that program will no longer be supported) and for the most part does not butcher them when you import them to the GPS.
||Posted - 22 févr. 2012 : 23:44:16
I'm looking for a facility that I suspect many others would welcome. I frequently find that the most acceptable route from A to D is not via B and C and is neither the "fastest" nor the "shortest" but is a mixture of A and B roads, short stretches of motorways and a few "yellow" unclassified roads. Just the sort of thing I am accustomed to composing on my desktop In MemoryMap or similar and downloading as a .gpx file into my handheld GPS unit and using on my bicycle. (Well, OK, not motorways on the bike, but you get the idea). The unit displays a rolling OS raster map with my route visible as a highlit line and I simply follow the map, just like the good old days.
I spoke to Garmin and yes, you can do this with a number of our models. I checked some Owner Manuals, downloaded from their website and sure enough, they say: "The device supports the following file types:
• JPEG and JPG image files
• Maps and GPX waypoint files from
So I buy a nuvi 2595LMT
I can't connect it to Mapsource. A couple of long tedious conversations later, it turns out that the previous adviser and the manual are wrong - you can transfer files (and only Routes not Tracks) only by using Basecamp.
A frustrating couple of hours later I have finally got a small route loaded into the nuvi. Scrutiny reveals that it's taken only some of my user defined waypoints. I try it in the car anyway, twice. The first time the routing goes around in circles; the second time it just stops halfway through the journey.
I know from my experience with handheld Garmins that their "satnav" autorouting is pants but I expected the in-car units to be workable.
Is there anyone out there who has cracked this?
||Posted - 06 oct. 2009 : 20:17:35
Glad I could help. As noted earlier in this topic, when converting from other maps, such as Google, this can happen even when the original waypoint has been placed very accurately, just due to map differences.
||Posted - 05 oct. 2009 : 02:42:16
Thank you! I experimented again and this time I carefully aimed between exits (not a piece of cake on CA91 where exits are only blocks away) and everything transferred to Nuvi as is.
Thanks again for your advice.
||Posted - 04 oct. 2009 : 16:35:39
The only time my 760 did this was if the intermediate point was too close to an on or off-ramp. Zoom way in while looking at your route in MapSource and see if it thinks you are calling for an exit. Also, how are your navigation prefs set in your nuvi?
||Posted - 04 oct. 2009 : 06:59:59
Can anyone explain crazy behavior of pre-programmed multipoint route with intermediate points placed on freeways (California)?
I have Nuvi 760, software version 4.8.
Often two-point route that MapSource offers does not sit well with me so I am bending the route placing fictitious intermediate points along the route. After making the route to my taste I transfer it to Nuvi. When I look at the final route recalculated by Nuvi I see ugly loops on freeways around my points.
Points that sit in streets have no problems, points located onto freeway where no street exits are nearby also work as intended. However, for every point having street exit within mile or two Nuvi plans exit to street, some nonsensical street traveling and return back to freeway. I place these points very accurately, say; if I drive on I605 north I place the point as I605-N etc.
Interesting that neglect of those loops around abnormal waypoint does not result in any Recalculating remarks, Nuvi silently agrees with my choice and continues just as if nothing had happened.
Looks as Nuvi considers every freeway waypoint as user error and tries to fix this error by going to the nearest street location.
Has anyone ever observed that erratic behavior of Nuvi 760? If yes, can you advise how to fix this?
||Posted - 27 sept. 2009 : 15:13:34
My experience was that most of the time the nuvi would properly send me to the next via or shaping point if I was off-route and it recalculated. I only had to reload once or twice, and that may have been due to flaky firmware behavior as much as routing.
||Posted - 27 sept. 2009 : 11:50:23
Yes, in the "off-route" mode it would be "manual" guidance only so not terribly practical but still handy in some situations.
I thought larelr2003 had mentioned this method in the Routing challenge: Coast to coast on a Vespa topic but can't see it now. He does say that in case of a recalc after getting off course you can always reload the original route, assuming you're back on it.
||Posted - 26 sept. 2009 : 23:18:08
No, I could not find any way to prevent recalc. Instead, I made sure to have enough "forcing" points that the route would not be destroyed when it recalcs.
I did not, however, try the off-road setting. My guess is that it would have caused trouble when I deviated from the route, either on purpose (some of the roads were totally unsuitable for a medium-size truck) or to go back and fetch a broken-down scooter. At that point, I =wanted= recalc to get me back on track.
||Posted - 26 sept. 2009 : 23:02:12
I was puzzled about multi-point routes so I came back to the guide ;-) One thing I thought I remembered reading is that you could prevent any recalc by switching to the "off-road" routing, obviously you would lose guidance so you'd need to look at the map to see where to turn, is that something you'd tried on your trip last year?
||Posted - 24 sept. 2009 : 13:31:06
The FAQ is stickied at or near the top of the forum.
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