Road and bridge height limiting device

The road and bridge height limiting device comprises a ground groove and a threaded rod, a guide rail is installed in the ground groove, sliding seats are arranged on the left side and the right side of the upper portion of the guide rail, the sliding seats are connected with the guide rail in a sliding mode, a first motor is installed on the outer side of the upper portion of each sliding seat, and a first transmission shaft is installed on the inner side of each first motor; the first transmission shaft extends into the mounting box to be connected with a driving wheel, the driving wheel is meshed with a driven wheel, the driven wheel is arranged on a threaded rod in a sleeving mode, and the threaded rod penetrates through a through hole in the upper portion of the mounting box to extend to the outside. The threaded rods on the two sides are sleeved with sleeves, telescopic rods are installed between the sleeves and comprise the left telescopic rod and the right telescopic rod, a rack is installed at the bo