Abstract: An improved safety barrier/ramp actuation mechanism for combination folding stair and platform wheelchair lifts which translate from one configuration to the other depending upon the purpose to be served and have a combination safety barrier/ramp at the outboard end of the platform, the mechanism comprising a triple link mechanism and internally contained piston and bellcrank for reciprocating said barrier/ramp, and a pressure relief for said system to prevent raising said barrier/ramp when a load is resting thereon in ramp position, and the invention includes new steps in the method of operation of the stair and lift combination to enhance the safety thereof.