This paper describes forward-collision warning system adapted for individual driver characteristics. Conventional forward-collision warning system has the problem to output warning signals excessively though the driver intends to stop the vehicle. The driver feels irritated by these useless warnings. The objective of this study is to develop an algorithm which solves this problem. In this algorithm, the warning output timing is determined to a value that the driver conducts braking action for possible collision avoidance when looking aside. In addition, the warning output timing is changed by foot position of the driver. From experimental result by young and elderly subjects using driving simulator, excessive output of warning signal was reduced without collision.