Vehicle control device and vehicle control method

A vehicle control device comprising:

• a computer memory configured to store vehicle trajectories in association with road segments of a map;
• an environmental sensor configured to detect traveling environment of a host vehicle;
• a processor configured to
• determine one of the vehicle trajectories along which the host vehicle is traveling,
• determine whether switching from the one of the vehicle trajectories to the other one of the vehicle trajectories is needed, and
• control a turn signal of the host vehicle according to a detection result of the environmental sensor in response to determining that the switching from one of the vehicle trajectories to another one of the vehicle trajectories,
• the vehicle trajectories including sensor-based motion histories of the host vehicle and/or other vehicles along the road segments or corrected motion histories obtained based on the sensor-based motion histories along the road segments.