Microscopic traffic simulation is a traffic analysis tool that provides a very detailed view of traffic dyamics in road networks, used for very specific purposes of analysis and de-sign of traffic systems. However the current practice has shown that quite frequently it can al-so be used either as a complementary tool in transport planning studies, providing a refined dy-namic view of sub -networks for a better decision making. lmporting data from an asaignment exercise into a microscopic simulator can also be a way of providing some of the default input data required in some cases by the microsimulator. The requiement of interfacing the macro approach on which EMME/2 is based, with the microscopic approach as it has been implamented in AIMSUN 2 lead to the devdopment of a specific methodology that has already been tested in some real life projects This paper prerents the recent refinemects and improvrements to this methodology. and on the design and implementation of the interfaces between EMME/2 and AIMSUN 2 based on this methodology The results are of some applicabons are presented and discussed.