Abstract: When driving a vehicle, constant speed drive may be engaged so that the vehicle can maintain, without any input from the operator, a desired speed, regardless of at least one of the slope on which the vehicle is travelling and the load it is carrying etc. Control of working vehicles may be very demanding on the operator, so it may be desirable to minimize any additional control burdens. The present disclosure may facilitate the engagement of constant speed drive in a vehicle with a non-direct transmission system by considering the stability of a speed of the vehicle and an engine speed demand from the operator.