Driving assist device

A driving assist device comprising:

• an information acquiring section capable of acquiring driving control information to be used for a driving control process with which an own vehicle follows a preceding vehicle which is running in front of the own vehicle on a same lane on a roadway;
• a driving control execution section capable of performing the driving control process of the own vehicle on the basis of the acquired driving control information;
• an interruption detection section capable of detecting an interruption of a preceding-vehicle following of the own vehicle, the own vehicle following the preceding vehicle in the preceding-vehicle following as the driving control process;
• and
• a deceleration section capable of decelerating a vehicle speed of the own vehicle by using a predetermined braking force when the interruption detection section detects the interruption of the preceding-vehicle following of the own vehicle in the driving control process performed by the driving control execution section.