Groove size self-checking device for road construction

The utility model discloses a groove size self-checking device for road construction. The device comprises a vertical rod and a left extension arm, vertical devices are fixed to the two sides of the lower end of the vertical rod, a control box is arranged at the top end of the upper side of the vertical rod, the left extension arm is fixed to the middle of the left end of the control box, and theright extension arm is fixed to the middle of the right end of the control box. The groove size self-checking device for road construction is provided with the left extending arm; the left extending arm and the right extending arm which are oppositely distributed can uniformly slide under the transmission action of the gear; and meanwhile, the gear is easily engaged with the first rack to achievea force transmission effect, so that the left extending arm and the right extending arm are accurate in transmission, high in efficiency, compact in structure, reliable in work, long in service life and stable in rotating spee