The instructions for the sat nav (2010 HSE) imply that an 'avoid' can only be applied when a route has been planned. In fact, you can store up to 10 permanent 'avoids' in the stored locations. Without it, the sat nav tries to take me up a single track unmade road to save about 10 yards of distance. My Disco 3 Garmin was the same.

The best thing to do is avoid the satnav altogether
Land Rover satnav's ain't the best  ______________________
2011 Full Fat RR 4.4 TDV8
2012 FL2 SD4 Auto HSE
2013 Kawasaki Versys 650

I always thought the 'avoid area' feature was for a Bonfire of the Vanities scenario or if in South Africa to avoid car jacking..... JT Upgraded to an ex demo, 7 mth old, Rimini Red/Ebony Napoli Auto HSE on 28th Jan 2011, added roof rails, mudflaps and side strips.
Gone - A great 57 Plate, Auto SE, Bought Feb 2009, Roof Rails and Mudflaps added on purchase. Blue colour, anything but drug dealer black.....

julytourist wrote:

I always thought the 'avoid area' feature was for a Bonfire of the Vanities scenario or if in South Africa to avoid car jacking..... JT

How about Lancashire?  Gone, 2007 TD4 SE Auto Baltic blue, clear side repeaters, full sized alloy spare.

English by birth..... Yorkshire by the grace of God.