[GeoffP]

this shows several simple steering methods if you are going that route. left/right (tank) control will not work well this year since friction is so low. remember that sliding (dynamic) friction is roughly half of not-sliding / rolling (static) friction. also keep in mind that velicity is not a variable in the equation for the force of friction. 4 wheel independent drive, limiting torque to just below the break point between static and dynamic friction, and positive steering will be the keys this year.