The present invention provides a traveling operation device that is configured so that the speed-change lock mechanism shifts from the speed-change locked state to the unlocked state when the brake operation mechanism is operated. The present invention also provides a traveling operation device including a forward-side speed-change pedal and a rearward-side speed-change pedal for operating a traveling stepless speed-change device provided in a working vehicle, wherein the forward-side speed-change pedal and the rearward-side speed-change pedal are arranged spaced apart in a vehicle width direction so as to define a footrest region in between at one of left and right step boards in the working vehicle. The present invention also provides a working vehicle in which the driver's seat is exposed and which includes supporting members for supporting a pair of left and right mud-shield foot-guards arranged on a front side with the driver's seat as a reference and a width indicator lamp detachable mounted to at least one of the pair of left and right foot-guard supporting members so that a light-emitting portion of the width indicator lamp faces forward.