A method for monitoring the condition of a bridge includes:stably positioning a video camera at a selected location with an unobstructed view of a selected portion of the bridge structure；collecting a video file of the structure over a selected total time interval；using a data processing system to analyze the video and calculate a physical parameter related to movement of the selected portion as a function of time, wherein the data processing system is controlled through a graphical user interface (GUI) having the following features: a display of a single video frame corresponding to a selected time；a movable area selector in the video frame to indicate the selection of an area of the structure for analysis； and,a display of displacement versus time for the selected area over the total time interval.The processor may perform some tasks, e.g., area selection, autonomously or via predetermined rules.
