A safety barrier for wheelchair lifts is disclosed, and more particularly a safety barrier assembly (10) which can be used singly or in opposed pairs to open automatically and mechanically in cafe-style, rotating 90° from a first closed or barrier position to a second, open, pass-through position. More particularly, these barriers may be used as barriers on wheelchair lift platforms (24) or at the door opening of a van or transit vehicles on which a wheelchair lift is mounted. The barriers (32) typically are shaped like the letter P with the lower most barrier member being spaced from twelve inches to two feet above the floor, and which are designed to prevent wheelchairs from rolling out of the van when the platform (24) has left the transfer level (vehicle floor), and as a safety barrier in the case of runaway wheelchair events. The preferred embodiment of the gate is mounted to a pivotal cam slot/bias spring assembly (14) which provides for stable open and shut positions with spring/gravity assisted closure. The preferred embodiment also includes a safety interlock switch circuit which prevents lift platform motion when the gate barrier is open.