STEERING ASSIST DEVICE

In a steering assist device, a main lane keep assist current value setting unit 51 sets a main lane keep assist current value Imr* that generates main lane keep assist torque according to a lateral deviation y and a lateral deviation change rate dy/dt. A sub lane keep assist current value setting unit 52 sets a sub lane keep assist current value Isr* that generates sub lane keep assist torque according to curvature ct of a target travel line Ls.