Abstract
This study aims to investigate the impact of the urban undersea tunnel longitudinal slope on the visual characteristics of drivers. 20 drivers were enrolled to conduct the real vehicle test of the urban undersea tunnel. First, the data of average fixation time and visual lobe were collected by an eye tracker. The differential significance was tested using the one-way repeated measures analysis of variance (ANOVA). Then, the difference between the up-and-down slope (direction) factor and the longitudinal slope (percent) factor on the two indexes were analyzed using the two-way repeated measures ANOVA. Second, by constructing a Lorentz model, the impact of the longitudinal slope on the average fixation time and the visual lobe were analyzed. Besides, a three-dimensional model of the longitudinal slope, average fixation time, and visual lobe was quantified. The results showed that the average fixation time and visual lobe under different longitudinal slopes markedly differed when driving on the uphill and downhill sections. The average fixation time and visual lobe under two factors were markedly different. Moreover, with an increase in the longitudinal slope, the average fixation time exhibited a trend of increasing first then decreasing; the visual lobe exhibited a trend of decreasing first and then increasing. The average fixation time reached the minimum and maximum value when the slope was 2.15% and 4.0%, whereas the visual lobe reached the maximum and minimum value when the slope was 2.88% and 4.0%. Overall, the longitudinal slope exerted a great impact on the visual load of the driver.
Highlights
The number of urban tunnels crossing rivers and mountains has gradually increased to adapt to the rapid development of the urban economy and regional expansion [1]
Undersea tunnels have the characteristics of long distance, large longitudinal slope, and high brightness of the hole [2]. us, compared with the general roads, undersea tunnels affect drivers’ physical and psychological burdens in terms of long large uphill and downhill slopes and poor sight [3]. us, exploring the visual characteristics of drivers in long large uphill and downhill slopes of undersea tunnels is of great significance to improve the traffic safety
Relevant research has not been conducted on the visual characteristics of drivers in the long and large slopes of undersea tunnel, and most studies have focused on highway tunnels and under-crossing tunnels
Summary
The number of urban tunnels crossing rivers and mountains has gradually increased to adapt to the rapid development of the urban economy and regional expansion [1]. Undersea tunnels have the characteristics of long distance, large longitudinal slope (usually 3%-4%), and high brightness of the hole (the effect of “black and white hole” is notable) [2]. Us, compared with the general roads, undersea tunnels affect drivers’ physical and psychological burdens in terms of long large uphill and downhill slopes and poor sight [3]. Us, exploring the visual characteristics of drivers in long large uphill and downhill slopes of undersea tunnels is of great significance to improve the traffic safety. Relevant research has not been conducted on the visual characteristics of drivers in the long and large slopes of undersea tunnel, and most studies have focused on highway tunnels and under-crossing tunnels. Green et al analyzed the factors influencing tunnel sight distance based on visual principles [7]. e study by Manser and Hancock
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