Visual fatigue is a fatal traffic safety hazard for drivers in the process of high-speed driving. Therefore

the analysis of the driving visual space of the driver in a quantitative way is an important path to reveal the relationship between driving safety and driving visual behavior. In response to these characteristics

such as a monotonous visual environment and a high proportion of viaducts in the urban expressway

this research adopted the automatic imaging technology of vehicle-mounted isometric and variable-distance for the simulation experiment

and the numerical analysis method is used to analyze the structural characteristics of the driving visual space between the common viaduct section and the zero-interface viaduct section in the urban expressway

to determine the composition and frequency of visual elements in the two typical spaces. Results show that the visual elements of the urban viaduct section are lower than the common urban roads in addition to the sky background. The main visual elements of the viaduct section are the bridge pavement with the sky as the background and the right-side street building

and the distribution of these elements is too balanced and simplification

thereby causing visual fatigue of the driver. In addition

the visual elements of the zero-interface viaduct section are in a state of scarcity for a long time

which is easy to cause negative driving psychology

such as anxiety

panic and instability. The reasonable design of traffic safety facilities to guide the driver's sight at the right time can effectively alleviate the driver's visual fatigue

and increasing the visual elements as the elevation reference is the most direct measure to eliminate the negative driving psychology of the zero-interface viaduct section.