It appears Google doesn't find New York and New Jersey's Holland Tunnel to be a safe mode of transportation.
If you try driving from Hoboken to Wall Street, Google will take you out of the way and take you through the Lincoln Tunnel as opposed to the more direct approach of the Holland Tunnel. It is true that the Lincoln Tunnel is ten years newer than the Holland Tunnel and also larger by having two more lanes but still, it is out of the way.
Here is a picture of the directions:
Notice the Holland Tunnel near the Route 78 sign lower down on the map. Seems like Google is really going out of their way to take you to a different toll booth.
First reports came of this 'bug' last Friday in the Google Maps Help forum. Nothing has yet to be done.
I wonder if there is a reason or just a weird directions bug. It is not like Google Maps isn't aware of the Holland Tunnel, they are, just click here and you will see Google Maps has street views from inside the tunnel.
Forum discussion at Google Maps Help.
Update: This is now fixed, see here for an update.