back button

You can if you have a model that offers a track log. Just make the track visible on the screen and follow it backward. It helps if you delete the tracks before beginning a trip to eliminate all the paths you've taken before but don't need for the trip back.

An alternative is to set up your route beforehand in MapSource. Save it to the GPS then "reverse" the route and save that (but under a slightly modified name). When you reach your destination just load the reverse track.

Cheers

The problem is that routes that are on roads cannot be easily just "reversed" because the routing has to take into consideration one-way streets, interstates, other divided roads, etc.

So it can't just go back the same way you came. It's actually a very complicated routing algorithm to get around this.

. . .Oddly enough, the GPS does its own recalculation of the route(s) received from Mapsource, sometimes coming up with unintended variances along the way.

Even Mapsource gets squirrely when doing the reverse of a route, thanks especially to things like exit and on-ramps as Motorcycle Mama has pointed out.

but, delorme street atlas gps does it, and if they can do it so could garmin.

I have used a technique to reverse multipoint routes on my nuvi's with some success. It only takes a minute or two. You call up the custom route for edit, then use "Manually Reorder" points. Move the Start to the Finish and the Finish to the Start. Then go back to the edit menu and select "Optimally Reorder Points", save the route and it is a reversal of the original.

Of course the caveats that MM identified come into play. If you have via points on one-way roads or in a specific lane of travel of a divided road, it will cause backtracking on the reversed route, and you will need to move these points to a correct lane / one-way street for the reversed route and recalculate. Also, if your original route was not optimal (for example if it was a zig-zag, circular or backtracking route), the "optimally reorder" may not give you a true reverse order of the via points. But I have used this method several times and in general have had good results.

setting your starting point as a favorite when you start the trip.
Then when time to return, select the favorite as a destination.

as i said at the beginning thats what i do, but 70 % of the time it takes us back a different route, even though there are no one ways etc.

Check out, too:

http://www.gpsreview.net/reverse-route/#more-3696

What I found interesting in this link is the statement that some newer GPS units base route calculations on time-of-day estimates for traffic. I wonder how widespread this new feature is now.

Well if you saved the location where you started from just use that info to get back to it, (where to and use the saved location.

I drove 200 miles from my home to VA Beach. My GPS gave me one route going down, and when I set the GPS to return home, it generated a significantly different route. The calculated times were within a few minutes and the distances were within a few miles. Actual time was quite different, because slower route was using two-lane state roads, whereas the faster route used a 4-lane divided federal highway. I can find no obvious reason why it should do this.

Scenery was nice both ways though...

My 855 leaves a track that I can follow back to the beginning of a trip. I just follow the little blue line.