A portable safety belt for use on a motor coach passenger seat is provided. The portable safety belt is formed of a single strap routed to form a closed loop for encircling a seatback and an open loop terminating at either end of the strap with a male and female buckle. The open loop is adapted as a lap belt for holding a passenger. A locking member disposed at a side of the closed loop provides interrelated adjustment of the open and closed loops to tighten the closed loop around the seatback.
