This working vehicle 1 is provided with: a traveling machine body 2 having an engine 5 mounted thereon； left and right traveling sections 4 for supporting the traveling machine body 2； a steering operation device 14 for changing the direction of movement of the traveling machine body 2； and left and right primary transmission/interruption members 48 for transmitting and interrupting power to the left and right traveling sections 4, and the working vehicle 1 is configured such that a primary transmission/interruption member 48 is operated according to the steering operation of the steering operation device 14, thereby interrupting power to a traveling section 4 on the inner side with respect to turning. The working vehicle 1 comprises, separately from the left and right primary transmission/interruption members 48, left and right secondary transmission/interruption members 111 and left and right speed reduction mechanisms 131. As the primary transmission/interruption member 48 is operated to interrupt power to the traveling section 4 on the inner side with respect to turning, a secondary transmission/interruption member 111 is operated and connected to the traveling section 4 on the inner side with respect to turning, and as a result, power for the traveling section 4 on the inner side with respect to turning is transmitted either through a speed reduction mechanism 131 or through both the secondary transmission/interruption member 111 and the speed reduction mechanism 131 to drive the traveling section 4 on the inner side with respect to turning, at a lower speed than the traveling section 4 on the outer side with respect to turning.Le véhicule de chantier (1) de l'invention comprend un corps de machine de déplacement (2) sur lequel est monté un moteur (5)； des sections de déplacement gauche et droite (4) pour soutenir le corps de machine de déplacement (2)； un dispositif d'actionnement de direction (14) pour changer la direction de déplacement du corps de machine d
