A riding lawnmower includes left and right wheels, at least one caster wheel, a lawnmower blade or reel, and a control section. The left and right wheels are independently driven by electric rotary machines to travel. The lawnmower blade or reel is driven for mowing. The control section, in response to turn instruction input by a turn operator, controls the left and right wheels according to preset standard setting conditions, or according to deceleration setting conditions which differ from the standard setting conditions, under which at least one of a vehicle movement speed and vehicle turning speed is decelerated more than under standard setting conditions. The riding lawnmower includes a section designating either standard setting conditions or deceleration setting conditions. In a riding lawnmower, left and right wheels are caused to turn around a turn center position corresponding to a turn instruction according to designated setting conditions.