Actually see here what carpool means from the person who implemented it ( it is therefore in reality no avoidance, but just an combined setting of no on several vehicles):

That's because the "carpoolness" of a way is specified by
having all of the access bits except for CARPOOL, EMERGENCY (and,
optionally, BUS) disabled. That's how it becomes a carpool way.

http://www.mail-archive.com/mkgmap-dev@lists.mkgmap.org.uk/msg04198.html

On 21.11.2011 19:54, Minko wrote:

Check it your self Felix, I'm not talking non sense. Chris confirmed this too.