To monitor safety of the road, traffic conflict technique which observes evasive action by driving a car had been proposed. This method assumes that frequencies of evasive action by a test car while it passes through certain road section have correlation with potential of accidents at the section. However, this method needs some more information about repeatability, reliability and practicality for practical use in road administration. Two national highway were selected for test section, and the tests were done in various condition to examine the items mentioned above. In the consequence, some quantitative results which are necessary in application of the test to road administration were obtained.