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 transition controller for transitioning between driving assist modes, characterized in that: the driving assist method includes, as the driving assist modes, a hands-off mode in which the driver is allowed to take their hands off a steering wheel, a hands-on mode that includes as a condition that the driver has their hands on the steering wheel, a steering wheel operation mode that encourages the driver to perform steering wheel operations, and a steering wheel assist deactivation mode in which the lane-keeping function is deactivated; acquiring information that a lane disappearance region, in which no lane that continues from a current lane can be recognized, exists along an extension of a travel route of a host vehicle during lane-keeping travel in which the hands-off mode has been selected; acquiring information on a lane disappearance start point when the lane disappearance region is known in advance, and setting a first position and a second position between a host vehicle position and the lane disappearance start point; requesting a mode transition from the hands-off mode to the hands-on mode when the host vehicle reaches the first position; requesting a mode transition from the hands-on mode to the steering wheel operation mode when the host vehicle reaches the second position; and performing a mode transition from the steering wheel operation mode to the steering wheel assist deactivation mode before the host vehicle reaches the lane disappearance start point when confirmation has been made that the driver is holding the steering wheel. the driving assist method includes, as the driving assist modes, a hands-off mode in which the driver is allowed to take their hands off a steering wheel, a hands-on mode that includes as a condition that the driver has their hands on the steering wheel, a steering wheel operation mode that encourages the driver to perform steering wheel operations, and a steering wheel assist deactivation mode in which the lane-keeping function is deactivated; acquiring information that a lane disappearance region, in which no lane that continues from a current lane can be recognized, exists along an extension of a travel route of a host vehicle during lane-keeping travel in which the hands-off mode has been selected; acquiring information on a lane disappearance start point when the lane disappearance region is known in advance, and setting a first position and a second position between a host vehicle position and the lane disappearance start point; requesting a mode transition from the hands-off mode to the hands-on mode when the host vehicle reaches the first position; requesting a mode transition from the hands-on mode to the steering wheel operation mode when the host vehicle reaches the second position; and performing a mode transition from the steering wheel operation mode to the steering wheel assist deactivation mode before the host vehicle reaches the lane disappearance start point when confirmation has been made that the driver is holding the steering wheel.