Automatic lane-keeping assist is generally turned on at all times with modern cars.
Keeping it on at all times sounds like a terrible idea for cars used in the US, because it's a developing nation with extremely poor road quality. In developed nations, it's probably OK because you can count on the road markings being good almost everywhere, but not in the US.
But yeah, you need to make sure there is a physical button on the steering wheel or somehere on the dashboard to easily enable/disable it. Otherwise it can be annoying.