Studying　driving　behavior　has　been　considered　an　important　approach　to　identifying　solutions　to　increase　roadway　level　of　service,　reduce　roadway　traffic　crashes,　improve　vehicle　designs,　and　develop　in-vehicle　safety　devices.　The　purpose　of　this　research　was　to　get　insight　into　the　effect　of　individual　differences　on　driving　behavior　and　traffic　flow　characteristics.　A　method　of　integrating　driving　simulators　and　traffic　simulation　was　developed　to　investigate　the　effects　of　driving　behavior　on　traffic　flow.　First,　a　cluster　analysis　was　performed　to　classify　drivers　into　three　categories:　aggressive,　conservative,　and　moderate.　Second,　the　driving　behavior　parameters　of　the　three　types　of　drivers　were　calibrated　for　traffic　simulation　models　using　the　experimental　data　collected　in　a　driving　simulator.　Then　the　effects　of　driving　behavior　on　traffic　flow　were　analyzed　by　traffic　simulation　techniques.　The　results　show　that　the　roadways　with　aggressive　drivers　have　the　highest　flow　rate　but　least　traffic　flow　stability.　Hence,　to　maintain　roadway　level　of　service　and　improve　traffic　safety,　it　is　necessary　to　develop　public　training　and　education　campaigns　to　reach　out　to　aggressive　drivers.