Problem: Evolving sandstorms on rural expressways in desert countries impair drivers' contrast vision and increase the risk of serious crashes due to delayed speed adjustments. Intelligent Transport Systems (ITS) such as Variable Message Signs (VMS) conveying warnings can be activated to address drivers’ speed adaptation before entering a low visibility zone. To improve drivers’ understanding of the hazard, a sandstorm animation visualizing turbulent sand and its consequences was designed and compared with a general warning pictogram, which is applied if no specific weather pictogram is available. Moreover, minimum warning distances of the VMS to the low visibility zone were tested (e.g., 300 m or 500 m).

Method

Sixty-three participants from the State of Qatar drove in a driving simulator through clear, transition, and low visibility conditions on a rural expressway. A repeated analysis of variances was conducted to examine the impact of the two on-road warning displays on driving behavior.

Results

The results showed that the sandstorm animation was similarly effective as a generic warning pictogram in reducing driving speeds before entering the transition and low visibility zone, irrespective of being displayed 500 m or 300 m away. However, the sandstorm animation resulted in consistent similar speed reductions within the low visibility zone, whereas the generic warning pictogram did either perform better or worse after several encounters with a sandstorm. Drivers did strongly agree that the animation is clearly referring to the issue of low visibility, which can be beneficial for recurring low visibility conditions.

Practical applications: 1.) Displaying a sandstorm animation is beneficial for rural expressway sections with recurring degrading visibility and low traffic densities, whereas a warning pictogram can be more effective in speed reductions if drivers expect additional traffic hazards. 2.) Roadway authorities have the flexibility to activate a VMS sandstorm warning even for minimum warning distances.

中文翻译：

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农村高速公路上的沙尘暴动画：可变能见度标志策略对低能见度条件下驾驶员行为的影响

问题：沙漠国家农村高速公路上不断发展的沙尘暴损害了驾驶员的视线，并增加了由于速度调节延迟而导致严重撞车的风险。在进入低能见度区域之前，可以激活传达警告的智能交通系统（ITS），例如可变消息标志（VMS），以解决驾驶员的速度适应问题。为了提高驾驶员对危险的理解，设计了一种沙尘暴动画，将湍流的沙子及其后果可视化，并将其与一般的警告象形图进行比较，如果没有特定的天气象形图，则将其应用。此外，还测试了VMS到低能见度区域的最小警告距离（例如300 m或500 m）。

方法

来自卡塔尔州的六十三名参与者在乡村高速公路上的清晰，过渡和低能见度条件下驾驶驾驶模拟器。进行了方差的重复分析，以检查两个道路警告显示对驾驶行为的影响。

结果

结果表明，沙尘暴动画在降低进入过渡和低能见度区域之前的行驶速度方面，与通用警告象形图一样有效，而不管显示的距离是500 m还是300 m。但是，沙尘暴动画在低能见度区域内导致一致的类似速度降低，而通用警告象形图在几次遭遇沙尘暴后的表现或好或坏。驾驶员确实非常同意动画显然是指可见度低的问题，这对于反复出现的可见度低的情况可能是有益的。

实际应用： 1.）显示沙尘暴动画对农村高速公路路段有利，因为能见度不断降低且交通密度低，而警告象形图在驾驶员期望额外交通危险的情况下可以更有效地降低速度。2.）巷道主管部门可以灵活地启动VMS沙尘暴警告，即使是在最小警告距离的情况下。