A work vehicle comprising: an engine; a traveling pump driven by the engine; a hydraulic circuit connected to the traveling pump; a traveling motor connected to the traveling pump via the hydraulic circuit; a rotational speed sensor that outputs a signal indicative of engine speed; a hydraulic pressure sensor that outputs a signal indicative of hydraulic pressure of the hydraulic circuit; and a controller configured to receive a signal from the rotational speed sensor and the hydraulic pressure sensor, determine whether the engine is in an over-rotation state based on the engine speed, determine an upper limit value of displacement of the traveling pump according to the hydraulic pressure of the hydraulic circuit such that an engine reverse drive torque transmitted from the traveling pump to the engine does not exceed a predetermined torque allowable value, determine that the engine is in the over-rotation state when the engine speed is equal to or greater than a predetermined first threshold, and the torque allowable value is a value of engine brake torque when the engine speed is a second threshold equal to or greater than the first threshold, and limit the displacement of the traveling pump to the upper limit value or less when the engine is in the over-rotation state. an engine; a traveling pump driven by the engine; a hydraulic circuit connected to the traveling pump; a traveling motor connected to the traveling pump via the hydraulic circuit; a rotational speed sensor that outputs a signal indicative of engine speed; a hydraulic pressure sensor that outputs a signal indicative of hydraulic pressure of the hydraulic circuit; and a controller configured to receive a signal from the rotational speed sensor and the hydraulic pressure sensor, determine whether the engine is in an over-rotation state based on the engine speed, determine an upper limit value of displacement of the traveling pump according to the hydraulic pressure of the hydraulic circuit such that an engine reverse drive torque transmitted from the traveling pump to the engine does not exceed a predetermined torque allowable value, determine that the engine is in the over-rotation state when the engine speed is equal to or greater than a predetermined first threshold, and the torque allowable value is a value of engine brake torque when the engine speed is a second threshold equal to or greater than the first threshold, and limit the displacement of the traveling pump to the upper limit value or less when the engine is in the over-rotation state. receive a signal from the rotational speed sensor and the hydraulic pressure sensor, determine whether the engine is in an over-rotation state based on the engine speed, determine an upper limit value of displacement of the traveling pump according to the hydraulic pressure of the hydraulic circuit such that an engine reverse drive torque transmitted from the traveling pump to the engine does not exceed a predetermined torque allowable value, determine that the engine is in the over-rotation state when the engine speed is equal to or greater than a predetermined first threshold, and the torque allowable value is a value of engine brake torque when the engine speed is a second threshold equal to or greater than the first threshold, and limit the displacement of the traveling pump to the upper limit value or less when the engine is in the over-rotation state.