Unusual routing

however this topic looks interesting.

It happened to me before.

To be sure, I always create and test route on the GPS unit itself using simulation mode. My guess is that routing algorithm could be different. And make sure your "via point" (waypoint) does not become something else after you transfer the route.

Are you using Garmin BaseCamp to build the route on the computer?

I have seen this before, in that the route built on BaseCamp does not end up the same once on the GPS. I always check the route on the GPS before using it. I do not trust the process from BaseCamp to the GPS.

For my series GPS (Montana), we have to switch to Direct Mode routing in BaseCamp, then transfer from BC to the GPS. Then once the route is on the GPS, choose the desired routing mode. There is an incompatibility between BaseCamp and some aspect of the GPS firmware, and the routes get caught in the middle.

I always build routes on the nuvi, and I always use via points so that the order of the route is exactly how I want it.

dobs108

Regardless of which software on the computer you used, you should never "assume" that a GPS (any GPS) will be following the same routing as you saw on a PC. Think avoidances, for one thing.

The safest way to do what you were doing would, I think, be to use via points as suggested above in the order that you want to go through them. Then, you really do not have to get into "simulation" mode on the GPS to check the routing. Just call up the route and press GO. Once the calculation is done, tap the top bar and look at the turn by turn directions.

What PC software did you use? Basecamp, I assume.

I found that once a route is created it will work great UNTIL the GPS says recalculating at that point it will recalculate its own way.
I have had this happen after stopping for gas a few times before I figured out what was happening.

The work around is go back to routes hit go and do not let it route you back to the start location. At that point it will take you to your next waypoint on your route.

That is how I do it on my 1450.

And the computer and GPS can and often does calculate the same route differently.

I have had some similar issues when doing multipoint routes with the 885. Not so much in skipping stops, but having the unit reorder the route after a stop. On a long trip with several programmed stops about 2/3 through the first day I had the unit suddenly decide I needed to go past a via point over 200 miles behind me. The route had to be stopped and then via points and stops I had aready passed deleted from the route. This was because the route showed the stop I was at as the current, but the next was the one 200 miles back so you couldn't tell the unit to continue the route from the current position.

From your description, I assume you checked the order of stops in the route after the screw-up and the stop wasn't just bypassed but was no longer in the route direcctions? The only remedy I can offer is to edit the route at every sop and eliminate previous stops completed.

routing is, probably, one of the greatest failings of current consumer GPS...I gave up on Garmin a few years back as, overall, their products had become all but useless for me...I switched to Tom Tom and have been, generally happier...however, even with the Tom Toms routing isn't perfect.

Many times I tried programming a route for the 1490 and, without fail, whether programmed using the 1490 or on the computer using map source, the route once entered and begun changed...I thought maybe it was the mode setting...switching between fastest, shortest, save gas...didn't help. Best I can figure is Garmin's internal dumb logic always defaults to shortest even if you tell it otherwise with a route. For instance in PA...if I want to go from Philadelphia to Lebanon to State College to Lancaster to DuBois...Garmin, after getting me to Lebanon would re-route to Lancaster (not State College) as Lancaster is close to Lebanon...the route would work perfect on the computer (though to force the route I would have to use a multitude of shorter waypoint which always made my favorites look like a frat house after homecoming weekend) but once installed did what it wanted.

I am no electronics wiz...nor am I a gadget guru...but if a device consistently fails what a man of clearly average, at least, intelligence tells it to do...if it is so hard to program that said man many times considers tossing said device out a car window at 75 on the freeway...it's time to move on.

To be fair to Garmin...Tom Tom is very cumbersome to program...if you want to go from A to B using roads 1-3-5...you can't say go to B using roads 1-3-5...you have to say go to B and then go back in and exclude 2 and 4...again, I might just be an imbecile but there should be some way to say go to B, use 1-3-5 and hit go...still Tom Tom, once programmed doesn't take you to 3 and then try to force you to go to 4 before taking you to 5...thus, though cumbersome, it is a vast improvement over my Garmin routing experience.

I love a GPS, I use one all the time but if I could change two things about the current crop of GPSs it would be, first, increasing the internal memory to hold map updates without having to buy external cards or jury rigging downloading or standing on your head spitting wooden nickels hoping your 3D buildings and junction view didn't burn to the ground (Garmin) and, second, being able to speak normal language to the GPS and saying go to A avoiding freeways, then go to B using fastest route then go to C taking route 123 all the way...

I wish I was smart enough to build such a machine...I wish those that are smart enough would stop with the Bluetooth and telephones and mp3 players and calculators and chicken soup recipes and just build a d@mn GPS that is easy to use, has powerful memory and stayed on course bending to your wishes and did not always try to tell you to do things its way...I am twice divorced (I know, can you believe it ) and I never imagined my third wife being a GPS

I had a similar thing happen with my 2597. I did a route with MapSource by just clicking a start and a finish with the map tool then used the move tool to change a section of the route. When I actually drove the route it ignored the section I changed and took over the routing, having me go straight instead of making a left turn to follow the change I made. It didn't say recalculating, it just changed the route. I have done routes this way with my 855 with no problem.

I probably could have used via points with the routing tool and not have a problem. I also know the 2597 has more routing options then my 855 has, and it being fairly new to me I may have something turned on that shouldn't be.

It is well known that a route calculated on the computer can be calculated differently on the GPS. So what needs to be done is let the GPS calculate the route and then review the route to make sure it is what was expected. If not, another design iteration is required on the computer, usually add another waypoint, or manually edit the route on the GPS.

My personal usage style hardly ever employs routing. Instead I tend to populate my recently used list with the waypoints I am likely to use, and then just one at a time navigate to them, quickly choosing the next off the recently used list as needed.

I realize this is not the answer for all cases, but I do think that some people try to press the routing mechanism into service in situations where it really does not suit them.

One of the posters above mentioned observing a change in routing preference when the unit went into recalculation. On my 3790 LMT it appears to me that recalculation always switches the preference to "faster" even if the unit is currently navigating to a waypoint under a "shorter" or "better fuel economy" regime. I regard this as an annoyance.

I normally do the routing on the GPS. Than I look at the Routing and review the route to make sure that is what I want. Works every time.

I have been doing routes in MapSource for many years, have transferred them to five different GPSrs and have never had a problem with the GPS following the route. The 2597 is the first one I have had a problem with.

There are a few suggestions that were written that may shed some light on this problem. I was using Garmin Express when this route was put into the gps. I have ran the route again but this time, I put the route in the gps instead of using the gps. Same result. After some calculations, it seems like the 4th stop didn't disappear until I had cut the vehicle off after the 3rd stop. The 4th stop is only about 900 feet down the road. What it looks like is that when I stop that close to the 4th stop, the gps is getting confused and causing it to skip the 4th stop. I will keep everyone informed when I find the answer as this is a problem for route drivers that deliver to stops that are close together.

Perhaps you may want to consider using sacrificial via points, points between two close route stops, to fake out the GPS.

And some GPS units have the option of allowing the GPS to reorder a route, to find the "optimum", make sure you don't have that option turned on if you want to have control.