Abstract
This paper deals with the driver's behavior to use the low speed range ACC system using a driving simulator (DS). In order to examine, the relationship between driver and the system is categorized into four phases, as the state from start to system-on, system-on to system-off, system-off to braking, and braking to stop. On these phases, the effects of the number of trials was analyzed. From these analyses, the outline of the driver's learning process to the system on each phase is found.