An object of the present invention is to provide a steering assist system capable of showing a driver an appropriate direction of steering operation in advance and correctly, and without impairing safety, and shortening an operation time during collision avoidance, in particular, reducing an idle running time. It is another object of the present invention to provide a vehicle mounted with such a steering assist system.A recommended steering direction determination unit 102 determines a recommended steering direction using measurements of a lateral position taken by an obstacle position measurement unit 101. After a collision determination unit 103 determines that risk of collision is high, a steering assist torque is generated using a first assist torque command value set by a first torque calculation unit 105. After a predetermined period of time after the driver starts steering or the steering assist torque using the first assist torque command value is generated, a steering assist torque is generated using a second assist torque command value set by a second torque calculation unit 106, the second assist torque command value being smaller than the first assist torque command value.