IT IS IMPORTANT TO ENSURE THAT ROADS ARE ASSIGNED TO THE APPROPRIATE LEVEL IN THE HIERARCHY ON THE BASIS OF THEIR PROPOSED FUNCTIONS. THIS PAPER AIMS TO CATEGORIZE THE FUNCTION OF LINKS OF A ROAD NETWORK IN A LOCAL CITY. TWO PHASE TRAFFIC ASSIGNMENT METHOD IS DEVELOPED FOR ESTIMATING ROAD NETWORK FLOW IN THE LOCAL CITY WITH PASSING TRAFFIC. THE PROPORTION OF TRIPS OF SPECIFIC OD PAIRS TO TOTAL LINK TRAFFIC VOLUME IS USED AS THE CLASSIFICATION BASIS. THROUGH THE APPLICATION TO THE NETWORK IN SAIJO CITY, THE FUNCTIONAL HIERARCHY OF THE EXISTING ROAD NETWORK SHOULD BE IMPROVED SO THAT THE MAIN DISTINCTION IS MADE AMONG PRIMARY, DISTRICT AND LOCAL DISTRIBUTOR ROADS.