This piece on Hack on Wednesday 27th Nov 2013 discusess how driving hungover can be just as bad as driving over the limit.
A study from the UK backed up by a similar study from the Netherlands found participants that had been drinking the night before but still had a BAC of 0.00 were just as impaired in a driving simulator as participants that were over BAC 0.05.
Chris Alfred of the University of England explained to Hack that the brain goes through a recovery period after drinking which extends past the point where all the alcohol is removed from your body.
Have a listen to the piece here