Prior to new map Update 2/2020

The only time I've been advised to leave a highway via an offramp, then return via the entrance ramp, was when it looked to me like the interchange had recent work done which realigned the highway and ramps. This could have possibly made the GPS device think I was on a different part of the current map's paved roads being used in the GPS.

I think I fell for this once and exited, then re-entered. After that, and since I traveled the route with recent construction a few times, I learned to ignore the exit/re-entry and just stick on the highway.

Back when this was happening, I think there were other areas recently realigned that caused the "snap to" feature of Garmin's On the Road devices to think that I was traveling on a frontage road when I was actually on the highway and that caused a lot of navigational miscues until the Garmin map was updated to include the realignments.

This may or may not have been what you experienced since for me, there was no Interstate Highway number change.

Since my settings are for the fastest route, I was somewhere I'd never been before. GPS told me to exit then mak a right and a left which took me through a small town with several traffic lights and some traffic.
Only to be told a little later again to enter the highway I had just left. The GPS tried that 2-3 more times but I zoomed out and saw it was doing the same shite again, so I ignored the GPS!

There can be several factors for this. I've found that if I had mistakenly set the route preference to shortest rather than fastest, it would suggest I get off the highway and take the service road when there was a long right hand curve making the service road technically the shortest way.

There may have been an incident that the traffic provider suggest an alternate route and now the incident has cleared.

Sometimes I think my Garmin is simply possessed. One time as I approached an intersection with a left turn lane at the traffic light which was the way I was going no mater what. Jack wanted me to turn right at that intersection and make a u-turn! The next day, I repeated exactly what I did the day before and Jack was happy for me to take the left turn. I have no idea what the turn right and make a u-turn was all about. This was in Colorado and perhaps Jack had been partaking in some of the locally available weed.

I see others have had this too....
We were in an un-familiar territory, and it took us a couple times to realize it was happening.... On the 2nd trip back we avoided the un-necessary exit.. and on our way home to NC we were directed that way yet again.... and we just laughed.... This was not a one off occurrence.... Each time we approached that intersection, from either direction, from three different destinations: Disney, Rental House, HOME..... 7 different times, it routed us off the exit to stoplight, and hack onto the road again!

Once upon a time, Delorme Street Atlas had this same problem. Zooming in on the area affected usually would reveal a spot where there was a small gap in the road. A cartographic error. SA did have the ability to create road segments that would normally fix the problem.

Without knowing the exact locations of the error points, it's hard to say what is going on with the Garmin map. One might be able to zoom in using Base Camp to examine the area. You might even have to go to Here.com to see if there is an error.

But even if you can find the problem, there's nothing you can do about it, except report the error at Here.

When I see an unexpected turn showing, I always inspect the route in that area to see if a detour is really in order and proceed accordingly. Most of the time, the detour is harmless, causing a minor inconvenience.

Once upon a time, Delorme Street Atlas had this same problem. Zooming in on the area affected usually would reveal a spot where there was a small gap in the road. A cartographic error. SA did have the ability to create road segments that would normally fix the problem.

Without knowing the exact locations of the error points, it's hard to say what is going on with the Garmin map. One might be able to zoom in using Base Camp to examine the area. You might even have to go to Here.com to see if there is an error.

But even if you can find the problem, there's nothing you can do about it, except report the error at Here.

When I see an unexpected turn showing, I always inspect the route in that area to see if a detour is really in order and proceed accordingly. Most of the time, the detour is harmless, causing a minor inconvenience.

You could set up a via point on the correct road and immediately PAST the incorrect exit your GPS is telling you to take. Set up a route that includes the via point and you should be good to go.

Phil

That would be fine and dandy if YOU knew about this beforehand! This comes at you unexpectedly !

I you have a lot of time to squander, simulate a route from just before the detour to the end of it. Then move the end point closer and closer to the beginning on the road being bypassed until you find eh spot that is causing the problem.

This is most easily done in Base Camp. Not so easy on the GPS unit, but it can be done.

Did I mention that we were in a new and unknown area?

I am Not going to pre check the route!!!

That would take longer to do than the traffic light we
Encountered to cycle....

My 3590 does that same thing in several places around Baltimore.

Don't know why.....