A pre-assembled walkway is provided, comprising an elongated walkway pan, a side railing subassembly, and a plurality of mounting brackets pivotally connecting the side railing subassembly to the walkway pan. The side railing subassembly comprises a plurality of vertical supports and handrails secured to tops of the vertical supports. The walkway is in a collapsed position when the side railing subassembly is pivoted in a first direction to the walkway pan with the vertical supports substantially parallel to the walkway pan and is in an erect position when the side railing subassembly is pivoted in a second, opposite direction with the vertical supports substantially orthogonal to the walkway pan.