A control system for a lawnmower includes a handlebar connected to the lawmnower for controlling direction and speed of travel of the lawmower based on a position of the handlebar relative to the lawnmower. The control system is connected to a drive system of the lawnmower such that changing the elevation of the handlebar adjusts operation of a number of wheel drive units and turning of the handlebar relative to the lawnmower adjusts operation of one wheel drive unit relative to another wheel drive unit.