A speed control device in a traveling work vehicle changes a speed of rotational drive power from an engine to drive vehicle wheels and includes: a target speed calculator determining a target speed, based on operation deflection of a speed change device. A vehicle speed controller adjusting a speed change ratio based on the target speed. A vehicle speed obtainer obtaining an actual vehicle speed. A forcible target speed modifier forcibly modifying the target speed to a lower speed based on operation of a braking device. A release can treat an operation of the speed change device as a trigger to cancel the target speed forcibly modified by the forcible target speed modifier, and conforming the target speed to the actual vehicle speed.