The steering work function is the amount of work the driver has to do on the wheel (torque integrated over angle or force integrated over distance) to steer the car through a maneuver.

Large steering work function values allow large trail values and manual steering. The downside at first is obvious - the driver has to put in more work at the wheel. She'll get tired faster than in an easier-to-steer car.

However, if the driver drives the car regularly enough, her upper body strength will improve - humans have inverse fatigue properties to materials if recovery's allowed between overloads. Have teams with too-heavy steering noticed a training effect?