Traveling under AP in the middle lane of 5 lanes, relatively light traffic, good lane markings, no sun glare, the car suddenly wants to veer sharply right into the empty lane. With my hands on the steering wheel, holding very lightly, I detected the jerk in the steering wheel, grabbed the wheel tightly, and corrected, probably before the car actually left my lane. Fortunately there was no car to the right, but it could have been serious. No, I did not accidentally signal for a lane change, or use the other controls, but having my fingers actually very lightly "gripping" the wheel (to feel what AP was doing) allowed me react very quickly. So, nothing visually apparent that would cause the AP to swerve or jog right. What I did do, a few seconds earlier, is give a voice command "Drive Home", and I think the route was being drawn (approximately then) when this unexpected "jog-right" event occured. So, just maybe, something in route calculation or drawing, or calculation of the expected energy usage graph, might have monopolized some resource that caused the AP to "glitch"? Only a maybe, I realize. In any case, a warning of an event with a high "pucker factor".