DRIVE ASSISTANCE DEVICE AND DRIVE ASSISTANCE METHOD

In a drive assistance device, a required space estimation unit estimates a required space which is a space required for a subject vehicle to complete a starting. A required time estimation unit calculates an estimated required time which is an estimate value of a time required to complete the starting at a time of starting the subject vehicle. A collision time estimation unit calculates an estimated collision time which is an estimate value of a time until when an obstacle reaches the required space. A start margin calculation unit calculates a start margin indicating a temporal margin for the subject vehicle to complete the starting until the obstacle reaches the required space based on the estimated required time and the estimated collision time. The notification processing unit notifies a driver of the subject vehicle of the start margin.