The invention involves a two-piece seat for a passenger-carrying vehicle with the seat being capable of complying with the federal requirements with reduced complexity. A steel plate is rigidly attached to the rotating seat back. The steel plate will prevent the seat back from rotating during normal use. If the bus were in a collision, a belted occupant would apply load to the rotating seat back through the seat belts. The steel plate would deform, allowing the rotating seat back to come forward. The fixed portion of the seat back remains in position to act as a passive restraint for any passengers seated behind this particular seat. Utilizing deformable steel plates to retain and control the operation of a rotating seat back equipped with 3-point restraints is a unique aspect to this invention. The plates will retain the rotating seat back in normal use to prevent vandalism to the seat belts, and can be easily removed so the seat back can be rotated forward for servicing the seat belts and upholstery covers.