[freerobby]

The steering wheel detects torque. Generally if your hands are on the wheel, they exert enough torque through natural movements for the vehicle to detect them. In rare cases, where a road is straight and a driver's hands are perfectly balanced, the car will flash a warning, in effect telling the driver to provide some brief feedback. The slightest of forces on the wheel will quell the warning (much less force than is required to move the steering wheel).

[selectout]

Are you talking about vehicles in general or Teslas? I've had a Model X for about a year now and can say that just having hands on the wheel definitely does not generate enough torque to deter the warnings on Autopilot, it definitely requires a "yank".

[freerobby]

Teslas. Maybe something changed but on my 2015 Model S I've never had to physically move the wheel in the slightest, just apply a little bit of pressure.