Self Organization and a Dynamical Transition in Traffic Flow Models
  A simple model that describes traffic flow in two dimensions is studied. A sharp {\it jamming transition } is found that separates between the low density dynamical phase in which all cars move at maximal speed and the high density jammed phase in which they are all stuck. Self organization effects in both phases are studied and discussed. 
Ofer Biham, A. Alan Middleton and Dov Levine