I had cruise set at 60mph on 2 lane highway. Their were rumble strips in center as well as edges of the road. I approached 2 slow moving vehicles (adaptive cruise was on) and then used turn signal, took over control myself disabling adaptive cruise. I pulled back in across the center mark after passing vehicles. When i crossed the 12′ wide center rumble strip my car immediately threw up a message on the screen and i could barely turn the wheel to prevent the car from driving into the ditch on my projected path back into my lane. The car got straight finally but the wheel was nearly impossible to turn. A few miles later, I approached my ramp to take and slowed down to 15mph under the ramp limit and it took nearly everything to get the wheel to turn 15 degrees to make my turn. i pulled off very slowly into a graveyard right off the road and parked the car. i took pictures of the messages on the screen ‘EPAS_w002 Steering may require increased effort’ on the center screen and the similar message on the center screen ‘Steering assist reduced steering may require increased effort’. I did a computer reboot (hold 2 buttons on steering wheel), left the car with my key and locked it ad walked away for a minute. I reapproached the car, it unlocked, and i turned the car back ON. Everything worked when i got on the highway with the exception of Autosteer (beta). It would not set, so i disabled it on the center screen. I turned it back on this morning (next day) and it is fully functioning again. I do not know how i didn’t end up in the ditch at highway speeds, but i feel this needs reported and a solution found before I or someone else loses steering. I’m not sure the center rumble strip had anything to do with it or if it was coincidental, but the car always ds a shimmy when you cross rumble strips in the center of the road (switching lanes) regardless of speed.