Abstract: An extended school stop sign, which may but need not be retrofitable, and barrier is mounted on a conventional school bus stop sign and extends further into the adjacent lane to reduce instances in which motorists pass a stopped school bus. A first frame is permanently secured to conventional stop sign mechanism. A second breakaway frame or arm is attachable to and detachable from the first frame, and extends beyond the conventional stop sign. If a vehicle strikes the second frame, it separates without significantly damaging the conventional stop sign mechanism. The extension arm can be moved between a retracted and extended position by the same mechanism that opens and closes the conventional stop sign, or with a new mechanism entirely.