Rack and Pinion in Action
The Lake Street bridge offers the best view of the rack and pinion during a bridge lift. This video shows the rack and pinion on the SW corner of the bridge.
The rack is the curved segment to the left hand side of the frame and the pinion can be seen turning at the bottom of the frame initially. The road surface comes into view later in the video. The audio provides the sounds characteristic of a lift. The bridge, not the camera is moving.