Study In Perception Theory And Method Of Highway Landscape Assessment

With ever increasing use of highway for transportation in modern life, highway has gradually become one of the major landscape elements of the roadside environment that people experience on a frequent basis. Highway is supposed to provide pleasant experience both visually and mentally rather than the conduit from one place to another, therefore, highway landscape planning and design has become more and more important in highway construction.Desirable highway landscape and design, integrated with highway engineering design, should fully apply engineering and quantitative methods in landscaping elements to form a unified engineering standard. The realization of quantization and engineering of highway landscape design is based on aesthetic evaluation of highway landscape elements, which needs the real-time perception of aesthetic subjects---passengers and the universal evaluation of the public. Object-oriented aesthetic methods are much valued and the public aesthetic acceptance of the landscape is regarded as the standard of measuring landscape quality in psychological paradigm of aesthetic evaluation. By measuring the public's attitude toward landscape, a relationship between landscape quality and landscape elements is established in the quantitative model. Three-dimensional simulation movie developed in this study mean to avoid the disadvantage of lack of on-site evaluation and photo realistic sense of space. Therefore, psychological paradigm is the most reasonable, reliable and effective way to make quantizing evaluation in highway landscape.Highway was regarded as the aesthetic object in this paper, and targeted research was conducted in its aesthetic characteristics, value orientation and psychological experience. The affects of roadside natural and cultural landscape elements on aesthetic perception were analyzed from the dynamic perspective. It played an important role for highway landscape evaluation and design to combine the principle of aesthetic perception with highway landscape dynamic features to create the highway landscape space fully reflecting visual enjoyment as well as transportation function.Based on the aesthetic perception principle for highway landscape, passengers are served as the dynamic aesthetic subjects. From the perspective of human physiology and psychology behavior in dynamic visual environment of the movement system, the physiological anatomy of visual perception is made, and the visual dynamic physiological and psychological characteristics of drivers, as well as dynamic visual and behavioral responses based on traffic safety were discussed. With the systematic views and methods, an analysis in highway transportation function and landscape environment was made to achieve harmony of safety function and aesthetics with a view to dynamic visual perception and psychological experience characteristics of passengers.On the base of the analysis of highway landscape aesthetic principle and dynamic visual perception and psychological characteristics of passengers, highway landscape environment is regarded as a multi-dimensional space integrating three-dimensional highway space with time and visual experience. From the three aspects of primary visual elements, coordinated visual elements and changeable visual elements, the primary elements of landscape space for highway landscape was discussed to clarify how to apply the elements of landscape space in highway landscape evaluation and design properly. As an important engineering element evaluating highway landscape space, space enclosure was analyzed and the relationship of space enclosure with aesthetic perception and spatial experience was also discussed. The layout of space sequence and structure model of highway landscape elements were also studied, which would lay the foundation for highway landscape evaluation system based on psychological paradigm.To determine how highway landscape elements related to highway users' dynamic visual perception and aesthetic experience, it is necessary to make a highway landscape evaluation to examine it. The study has harnessed the power of GIS (Global Information System) and VNS (Visual Nature Studio) to produce a number of different types of experimental landscape visualizations, in the form of two-dimensional images and three-dimensional animation video clips, to make a real-time aesthetic evaluation and investigate the relationship of landscape features including topography, landscape elements and visual enclosure with scenic preference. Integrating the use of the theory of "Peak and End"and "Ball Effect" in the sequence layout and space planning of visual landscape elements, a procedure for measuring the scenic quality of the highway landscape and explaining how landscape features relate to the visual perceptions of drivers by collecting and analyzing the highway landscape visualizations are described then, which would provide designers and decision-makers with a framework for incorporating multi-modal elements and their relationships into highway landscape planning and design.Based on the study of dynamic physiological and psychological characteristics of highway users and the aesthetic evaluation of highway landscape elements, highway region could be divided into different landscape regions with mutual coordination: landscape feature unit planning region, landscape visual planning region, landscape scale planning region, as well as landscape focusing planning region according to the topography and scale features of the region as well as drivers'visual characteristics in highway landscape planning and visual design, which could unify highway landscape form design and transportation functional characteristics with visual requirement of highway users to make highway landscape design more reasonable and effective. The analysis of landscape characteristics, terrain structure employing visual line method and site condition based on geographical features was then carried out to determine the visual features of highway landscape and guide landscape planning and integrated visual design.