A driving assistance device includes: a first member rotatably supported by a first member rotational shaft; a second member rotatably supported by a second member rotational shaft; an operation lever rotatably supported by both a first lever rotational shaft and a second lever rotational shaft, the first lever rotational shaft being provided at the first member, the second lever rotational shaft being provided at the second member and disposed toward a front side relative to the first lever rotational shaft, the operation lever including an extension part extending from the first lever rotational shaft toward a rear side; and a transfer member driving a generator that generates at least one of braking force or drive force for the vehicle in accordance with an operation of the operation lever.