Don't Understand Routing Sometimes......

I get that sometime too, but sometime it has to do with what the GPS considered "convenience" such as turn right is easier than left type of deal, U turn vs no U turn ...

GPS' tend to be literal, so the shortest may avoid one way streets etc. hence, the different routes. I believe most people have it set for fastest, which is generally the best all around.

This isn't the answer you want, but someone may elaborate further. Logically we think if we go from A to B we would go back from B to A the same way. That's the way we think. In most cases, the GPSr will do the same thing, but sometimes it decides the return route should be different. It may be the way back is something like 20' shorter.

Try the quickest route instead of shortest and see what that does. Save gas and do this in simulation mode and then look at the complete route.

If we use the GPSr to plot routes in areas we are familiar with, it will do things that bug us to no end at times. Where it shines is to take us somewhere where we have no idea how to get there and we are happy in our bliss.

I use QUICKEST and the Garmin 855 and 1490 do the same thing. Route A to B and B to A are not the same. This is one of the things that I don't like but overall Garmin is the best GPS brand I have ever owned and I have had GPS's for more than 10 years.

Are avoided it seems by the routing engine... and it seems to want you to arrive with your destination to your right.

I keep my 250 on shortest distance around my local city. I feel this gives me more interesting routing than fastest, and I'm always free to disregard the suggestions and let it reroute.

Recent I've seen some interesting things though. Although I have not changed the maps or firmware in over 10 months, and I don't have a trafic receiver, the GPS has started taking different routes from the same point to "home" than it used to take over the spring and summer! Nothing is wrong with either route (although the one this spring was "more interesting" in that it took more "back roads"). I just can't figure out how or why the nuvi with the same maps and firmware changed its mind about what it thought was the shortest route. And I've seem this behavior from more than one place, with the nuvi coming up with different routes than it used to.

Another thing that I thought was strange about "shortest route" operation happened the other day. I was just over 4.9 miles away from my house, actually the nuvi called it 4.9 as I turned at the traffic light. The nuvi, on shortest route setting was routing me home, but I didn't want to go the way it was telling me, I felt that if I made a right turn I would be on as good or better of a road, have less traffic, avoid three traffic lights, and I even felt that my route was a little shorter. So I took the turn, then pulled over, let the nuvi recalculate, and looked at the last "page" of the new route. Rather than 4.9 miles from my house, the nuvi said I was only 4.3 miles (and I had gone far less than 1/10 of a mile from where I saw the 4.9 mile reading). And it estimated that I would get home 3 minutes faster on my route. And, perhaps worth mentioning because of the above post, it approached my house and even the road my house is on from the same direction, so there was no right vs. left bias in the bad choice to route me a longer way. So the feature is still interesting, but it sure shouldn't be trusted over good judgment.

I've had mine route me at times even though I knew where I was going, just to see what it would suggest. It gave me some suggestions that I thought were a bit strange, but I followed them &, to my surprise, found a few that ended-up being better than the way I had always taken in the past.

However, I'm without mine for the next 10 days or so as it lost its marbles & thought it was July of 2029.

Being new to the auto GPS devices, but having experience with marine systems, I can't see why they don't let you preview a selected route prior to trip start. And an option to select a different route before starting would be nice too. Maybe the GPS will take me through an area that's not safe to travel.
I'm not the type of person who'll blindly follow a route. Not that I don't trust it, I just like to know where I'm headed and how I'll get there. Maybe there's construction with slow traffic, a major accidet that shut the road down, etc. I know the traffic system will tell me about it but if I know about it ahead of time I could select a different route.

Maybe I'm asking too much.

Once the nuvi has calculated the route and you are on the map display, touch the green bar at the top of the screen followed by the button at the bottom of the next screen and you will see the route end-to-end. Should you desire to route around a particular area, add a via to the route that will take you around it.

I believe some models limit the number of vias and some don't reorder multiple vias in an efficient manner. I know the 750 does and would expect the 765T would but you need to check the features to be sure.

I have used the "Detour" option a couple of times to get the GPS to go the way I want it to. Other than that I think it is built in to the programming to take main roads for as much as possible.

I have noticed this on my trip home from work. A fairly simple route but the GPS wants me to take the main road into town the the side street. But if I take the side street about 2 miles before where the GPS wants I avoid traffic, lights and such. It's also about half mile shorter distance wise. I'am set for "Shorter Distance" also.

Yeah, I've learned the hard way that I need to double-check the Garmin routing. About a month ago I was in Portland, Or wanting to go to Astoria. I've made the trip before but not in a couple of years. I punched in the destination address, choose "fastest route" and then took off. It was dark at the time, but I wasn't recognizing where I was. Turns out it had routed me on a pretty wild goose-chase that culminated with some pretty twisty/windy roads through Nat'l forest that could have easily had a locked gate had there been enough snow.......by that time I was an hour into the trip and would have had to completely turn around and take another 3 hours to get there.....

Remember a few years ago when the Kim family from SFO got stranded following their GPS from Southern Oregon out to the coast via Bear Camp Rd? They got 1/2 way there and got stuck in the snow--Mr Kim wound up dying from exposure when he went to get help......and another family got stuck in the same place just last week!

So, bottom line is that it's a good idea to check the route first to make sure it's taking you on a SAFE not just fast route!

Thank you TXVer and ORnonprophet!

The manual is lacking for detailed info like this. If it wasn't for people like you and places like this we'd all be lost.

ORnonprophet, I know what you mean about round-about directions. Last weekend we were headed to a store and used the GPS to get there. We knew where it was but wanted to see where the GPS would lead us. Talk about round-about directions. I could have gotten there quicker on my own. The GPS distance may have been shorter but time was longer.

Too bad about Mr Kim and his family. We'll be hearing more stories like that in years to come.

In another post someone said you shouldn't disengage your brain when using a GPS. Or something to that effect.