Visual communications of transportation system: Using information design to strengthen the legibility of transit maps

This thesis developed design solutions to enhance the legibility of transit maps by using information design knowledge. The author followed a user-centred approach to observe participants' reading behaviour and provide design solutions that meet user needs and expectations. In this study, the transit map is re-defined as an information design material rather than a cartographic map or a computerised diagram. The transit map design is divided into three main topics: information communication, visual design, and user performance. China's high-speed railway map is used as a case study where user performance tests are conducted to ascertain whether re-designing the map according to information design principles improves the map's legibility and makes it more user-friendly. The main focus is on information communication effectiveness, including map legend and instructional systems on the map; and on the visual design elements, including colour system, transit line layout, transfer signs and typography, etc. Finally, design guidance is established for transit maps based on the literature review and on the research findings of this study. This guidance is aimed at providing designers and researchers with both theoretical and practical design suggestions. Several research methods are included in this research study. Literature was reviewed to establish the theoretical basis for the empirical tests and relevant evaluation standards. Eye-tracking testing helped identify the map's strengths and potential design limitations in terms of information communication and visual design. It also assisted in observing users' reading strategies and habits based on the eye-movement data. The user performance tests helped evaluate the legibility of the existing map and the revised maps in terms of reading speed, information searching accuracy and route planning quality. The interviews and questionnaires helped collect users' opinions and suggestions, which reinforced the analysis of the experimental results. The results indicate that information design plays a vital role in transit map design in many aspects. The information communication quality of the map legend can largely affect the legibility of transit maps; users showed a faster reading speed and better information searching accuracy after the necessary instructions were visualised. The colour system showed its unreplaceable advantage in transit map visual design, especially in distinguishing and grouping different categories of travel information and map functions, such as different transit lines, services and icons, etc. In addition, a new colour-coding mode for transit lines that combines both qualitative and sequential schemes was created. Its effectiveness was then tested through usability testing. Users' reading speed and comfort were improved after the colour system was re-coded based on the new standard. This research also breaks Beck style (45°octolinear layout) in transit line schematical layout, widely recognised as "golden standard". The test results show that 60° octolinear layout could be the most suitable layout for the North-south direction middle-complex network. Moreover, the study shows that the visual design of micro visual elements (e.g., interchange icons, station labels) should always assist the information communication of the macro transit line layout. The test results would not be applicable to real-life contexts if the design of individual elements was investigated separately from the whole information design structure. The empirical research findings from this study are an essential contribution and a good demonstration that information design is of great importance to cartographic design. The study demonstrates a successful example that evaluated, improved and tested the legibility of a transit map by using existing information design principles and theories. The principles that then also emerge from this study are a strong contribution to knowledge in the field of information design and will provide valuable insight to researchers and designers. In addition, the methodologies used in the research can also support information design research beyond map design, such as information reading materials that contain various categories of instructions and data.