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 has been met during lane-keeping travel in which a hands-off mode has been selected as the lane-keeping assist mode, the traveling condition being that an actual vehicle speed of the host vehicle exceeds a speed limit of a roadway on which the host vehicle is traveling, and the hands-off mode allowing the driver to remove their hands from the steering wheel; 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 in that: the driving assist method further comprises: determining whether or not the driver has performed an accelerator-depressing operation during lane-keeping travel in which the hands-off mode has been selected; requesting the driver to hold the steering wheel upon determining that the driver has performed the accelerator-depressing operation; and the switching of the mode from the hands-off mode to the hands-on mode being performed upon confirming that the driver is holding the steering wheel. 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 has been met during lane-keeping travel in which a hands-off mode has been selected as the lane-keeping assist mode, the traveling condition being that an actual vehicle speed of the host vehicle exceeds a speed limit of a roadway on which the host vehicle is traveling, and the hands-off mode allowing the driver to remove their hands from the steering wheel; 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 in that: the driving assist method further comprises: determining whether or not the driver has performed an accelerator-depressing operation during lane-keeping travel in which the hands-off mode has been selected; requesting the driver to hold the steering wheel upon determining that the driver has performed the accelerator-depressing operation; and the switching of the mode from the hands-off mode to the hands-on mode being performed upon confirming that the driver is holding the steering wheel. assessing whether or not a traveling condition has been met during lane-keeping travel in which a hands-off mode has been selected as the lane-keeping assist mode, the traveling condition being that an actual vehicle speed of the host vehicle exceeds a speed limit of a roadway on which the host vehicle is traveling, and the hands-off mode allowing the driver to remove their hands from the steering wheel; and the traveling condition being that an actual vehicle speed of the host vehicle exceeds a speed limit of a roadway on which the host vehicle is traveling, and the hands-off mode allowing the driver to remove their hands from the steering wheel; 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 in that: the driving assist method further comprises: determining whether or not the driver has performed an accelerator-depressing operation during lane-keeping travel in which the hands-off mode has been selected; requesting the driver to hold the steering wheel upon determining that the driver has performed the accelerator-depressing operation; and the switching of the mode from the hands-off mode to the hands-on mode being performed upon confirming that the driver is holding the steering wheel. determining whether or not the driver has performed an accelerator-depressing operation during lane-keeping travel in which the hands-off mode has been selected; requesting the driver to hold the steering wheel upon determining that the driver has performed the accelerator-depressing operation; and the switching of the mode from the hands-off mode to the hands-on mode being performed upon confirming that the driver is holding the steering wheel.