PROBLEM TO BE SOLVED: To provide an arousal determination device appropriately performing arousal determination even when a traveling environment is changed.SOLUTION: The arousal determination device for determining a drivers arousal includes a steering operation detection means 240 which detects a steering operation quantity or steering force of the driver a counter means which adds a counter value according to the elapsed time in which the drivers steering operation quantity or steering force is a predetermined value or less an arousal reduction determination means 250 which determines a reduction in arousal when the counter value is a criterion value or less a traveling environment recognition means 230 which recognizes the traveling environment of an own vehicle a criterion value switching means which switches a plurality of criterion values according to the traveling environment and a counter value setting means which sets, when the criterion value switching means performs the switching of criterion value, a counter value after switching based on the criterion value and counter value before switching, and the criterion value after switching.COPYRIGHT: (C)2010,JPO&INPIT【課題】走行環境が遷移した場合であっても適切に覚醒度判定を行う覚醒度判定装置を提供する。【解決手段】ドライバの覚醒度を判定する覚醒度判定装置を、ドライバの操舵操作量または操舵力を検出する操舵操作検出手段240と、ドライバの操舵操作量または操舵力が所定値以下である状態の経過時間に応じてカウンタ値を加算するカウンタ手段と、カウンタ値が判定値以上となったときに覚醒度低下を判定する覚醒度低下判定手段250と、自車両の走行環境を認識する走行環境認識手段230と、走行環境に応じて複数の判定値を切り換える判定値切換手段と、判定値切換手段が前記判定値の切換を行うときに、切換前の判定値及びカウンタ値と、切換後の判定値とに基づいて切換後のカウンタ値を設定するカウンタ値設定手段とを備える構成とする。【選択図】図1
