Document Type


Publication Date





The Volpe Center developed a questionnaire to examine the representativeness of symbol shapes and the usefulness of information depicted on Low Visibility Operations/Surface Movement Guidance and Control System (LVO/SMGCS) paper charts. One-hundred forty-four pilots were shown a series of symbol shapes and responded “Yes” or “No” to whether they considered each symbol shape representative of a given information type. Symbol shapes were presented at increasing levels of context. Pilots then rated the usefulness of information depicted on LVO/SMGCS charts. Pilots identified representative symbol shapes for a geographic position marking, instrument landing system (ILS) hold line, runway guard lights (RGL), stop bar, and the combination of RGL and a stop bar. The general shape was usually perceived as representative regardless of variations in features such as border or fill. Pilot opinions of usefulness generally reflected findings for symbol shape representativeness.