Abstract: An adjustable adapter bracket for a railroad-highway crossing gate and signal installation for permitting the elongated gate arm to be shifted laterally to avoid interference with overhead obstacles. The adapter bracket is fixedly attached to the ends of a pair of gate supporting arms and includes upper and lower U-shaped strut members each of which is provided with at least two longitudinal rows or lines of apertures. A breakaway gate arm connector including a pair of apertured mounting plates is selectively positioned along the length of the U-shaped strut member and is securely fastened thereto by a plurality of bolts and nuts. A plurality of reinforcing spacer members are positioned between and are bolted to the upper and lower U-shaped strut members to reinforce and strengthen the adapter bracket.