Auto zoom function on Oregon maps

[Auntie Helen]

I accidentally switched on the 'auto zoom' function on the Oregon - and the maps seem to periodically zoom in and out. It confused me initially as I wasn't sure what it was up to. But I can't tell if it just does it at particular times or if it's speed/distance to junction related. There's no info on the Wiki. Does anyone know how this works?

[tom_e]

I think it only does anything when it's giving you turn by turn directions.  Then it zooms in a bit as you approach the junction, and back out again as you leave it.  How far out seems to be speed dependent.  Seems to work nicely for me.

If you fiddle the zoom by hand it seems to leave you alone until it gets to the next junction, then start moving again.  ISTR it isn't clever if you manually adjust as you approach, it tries to help anyway rather than leaving you alone.