A driving assist method that includes a vehicle speed/headway control function and a lane-keeping function as driving assist functions to assist driving operations by a driver, and that uses a mode-switching controller for switching lane-keeping assist modes that assist a host vehicle to remain within a lane during travel, the vehicle speed/headway control function being for performing a vehicle speed control based on a set vehicle speed, and the lane-keeping function being for assisting a host vehicle to remain within a lane during travel, the driving assist method comprising: assessing whether or not a traveling condition that an actual vehicle speed of the host vehicle exceeds a speed limit of a roadway on which the host vehicle is traveling has been met during lane-keeping travel in which a hands-off mode that allows the driver to remove their hands from the steering wheel has been selected as the lane-keeping assist mode; and switching the mode from the hands-off mode to a hands-on mode that has as a condition that the driver has their hands on the steering wheel upon assessing that the traveling condition that the actual vehicle speed exceeds the speed limit has been met, characterized by determining whether or not the driver has performed a set vehicle speed changing operation to raise the set vehicle speed above the speed limit during lane-keeping travel in which the hands-off mode has been selected; and the switching of the mode from the hands-off mode to the hands-on mode being performed upon determining that the driver has performed the operation to raise the set vehicle speed and the actual vehicle speed has risen to at least a vehicle speed assessment value found by adding an error allowance to the speed limit. the vehicle speed/headway control function being for performing a vehicle speed control based on a set vehicle speed, and the lane-keeping function being for assisting a host vehicle to remain within a lane during travel, the driving assist method comprising: assessing whether or not a traveling condition that an actual vehicle speed of the host vehicle exceeds a speed limit of a roadway on which the host vehicle is traveling has been met during lane-keeping travel in which a hands-off mode that allows the driver to remove their hands from the steering wheel has been selected as the lane-keeping assist mode; and switching the mode from the hands-off mode to a hands-on mode that has as a condition that the driver has their hands on the steering wheel upon assessing that the traveling condition that the actual vehicle speed exceeds the speed limit has been met, characterized by determining whether or not the driver has performed a set vehicle speed changing operation to raise the set vehicle speed above the speed limit during lane-keeping travel in which the hands-off mode has been selected; and the switching of the mode from the hands-off mode to the hands-on mode being performed upon determining that the driver has performed the operation to raise the set vehicle speed and the actual vehicle speed has risen to at least a vehicle speed assessment value found by adding an error allowance to the speed limit. assessing whether or not a traveling condition that an actual vehicle speed of the host vehicle exceeds a speed limit of a roadway on which the host vehicle is traveling has been met during lane-keeping travel in which a hands-off mode that allows the driver to remove their hands from the steering wheel has been selected as the lane-keeping assist mode; and switching the mode from the hands-off mode to a hands-on mode that has as a condition that the driver has their hands on the steering wheel upon assessing that the traveling condition that the actual vehicle speed exceeds the speed limit has been met, characterized by determining whether or not the driver has performed a set vehicle speed changing operation to raise the set vehicle speed above the speed limit during lane-keeping travel in which the hands-off mode has been selected; and the switching of the mode from the hands-off mode to the hands-on mode being performed upon determining that the driver has performed the operation to raise the set vehicle speed and the actual vehicle speed has risen to at least a vehicle speed assessment value found by adding an error allowance to the speed limit.