We have a whole group of Directories that send traffic but its not the quantity of traffic that is the key, its the quality of traffic and whether that traffic converts
The only directories that I know of that pass quality traffic are part of a niche specific community and they are generally paid.
I don't really track it but on Linkspub we've launched a unique type of search where the users can search for sites within specifid domain tld's For example mortgage companies in uk http://www.linkspub.com/search/?q=mortgage+.uk&Pbtn=Search I see the number of searches increasing so I guess that my Linkspub is sending people traffic.