One or more vehicle steering measurements of a vehicle may be measured. One or more expected vehicle steering measurements may be calculated, each calculated expected vehicle steering measurement corresponding to one of the measured vehicle steering measurements. At least one difference between one of the measured vehicle steering measurements and its corresponding calculated expected vehicle steering measurement may be calculated. A speed of the vehicle may be measured. One or more current threshold values may be calculated based on the measured speed, each of the current threshold values corresponding to one of the measured vehicle steering measurements and its corresponding calculated expected vehicle steering measurement. An automatic vehicle control system may be deactivated when one or more of the calculated differences exceeds its corresponding current threshold value.