Abstract: A threshold barrier assembly includes an illumination system to facilitate visibility of the barrier assembly while mounted in a doorway or on a staircase, thereby reducing the risk of a trip hazard. The barrier assembly can include a frame comprising a pair of upright frame members connected to a lower cross member, and a barrier door comprising an upper horizontal cross member pivotally connected to the frame, a lower horizontal cross member, and vertical members connected between the upper and lower horizontal cross members. At least one illumination element is installed in at least one of the lower cross member, the upper horizontal cross member, or one or more of the vertical members. An integrated controller can control illumination of the illumination system based on a predetermined sequence, or detected environmental or operating conditions.