"Lost" custom avoidance.

See for more info and Garmin faqs:

http://www.poi-factory.com/node/40271

From the currently-last post in the above thread, it looks like a Custom Avoidance needs to be reset after each map update if a road was chosen. But if set up as a rectangle (Custom Area), it may be preserved.

Thank you, I missed that post. So much to keep up with!!

I wondered about that.

I had a road segment that was under construction last year setup as an avoidance. It survived several map updates, and I finally removed it when the construction and detour were complete.

Are you talking about a single point avoidance located on a road?

It was a road segment. In fact I had a couple, both due to bridge reconstruction and they were both "lost" though the Avoidance screen said they existed and were enabled.

As jgermann surmised in that thread. An area avoidance is set by coordinates that are likely maintained as layer, independent of map version. A road avoidance on the other hand, appears to be tied to the road within the map and that is lost whenever the map is updated or restored.

Whenever I select a destination from my house, there is a particular dog-legged residential street where Jack's old girlfriend must live as he insists I go that way and he used to get upset if I bypassed this turn. My newer GPS supports road avoidance and now he quietly bypasses this street, but I noticed that after a recent map update, Jack was up to his old tricks. It seems like the alternative to keep him on the straight and narrow is to set an area avoidance for that street.

Road avoidances are reset because coordinates are used to mark the road to be avoided. Roads between different map versions can vary where exactly the roads sit on the actual GPS coordinates. A long time ago when I used MapSource, I would have multiple versions of City Navigator installed and it was quite easy to toggle between the different map versions...you could actually see some of the roads displayed shift ever so slightly.

Granted, not all of them shift of course and the shift as I mentioned could be *very* slight between map versions. This shift could be enough of a factor to totally invalidate whatever road avoidance you had setup and throw everything off.

Not sure if mine still does this, but sounds similar. Anytime I would get a map update my defined routes would recalculate and display and navigate by drawing a straight line between the start and destination, regardless if there was a road there or not (most times not). Many times if would tell you to turn right or left which would be off the road where only trees resided. Only fix was to reload the routes, hopefully you had saved them.

This is due to how the map based avoidance works--it points to the specific road on the map. When the maps are updated, all the roads are replaced, so the avoidance you set no longer points to anything.

Good to know