Experimental study on the effectiveness of warning methods for expressways in wind-sand environments

Wind-Sand Environment (WSE) poses a serious threat to driving safety on expressways, particularly as sand-covered road surfaces and reduced visibility significantly increase driving risks. Therefore, scientifically sound and effective early warning methods are crucial for ensuring vehicle safety in wind-sand conditions. This study systematically evaluates the effectiveness of seven conventional warning methods-fixed warning sign (Sign.A), deceleration marking (Sign.B), reflective road stud (Sign.C), variable speed limit sign (Sign.D), variable message board (Sign.E), voice warning (Sign.F), and guidance sign (Sign.G)-across blowing sand sections, accumulated sand sections, and blowing-accumulated sand sections through driving simulation tests, integrating vehicle dynamics, driving behavior, and physiological indicators.

Thirty drivers were recruited for a driving simulation experiment, and their driving behavior data under different scenarios were collected, including five types of metrics: average driving speed, standard deviation of longitudinal acceleration, standard deviation of extreme steering wheel angles, entropy value of steering wheel angles, and extreme value of Electroencephalography (EEG) β/α waves (β/α). The Criteria Importance Through Intercriteria Correlation (CRITIC) method was employed to determine objective weights, and a Criteria Importance Through Intercriteria Correlation-Technique for Order Preference by Similarity to Ideal Solution (CRITIC-TOPSIS) comprehensive evaluation method was constructed to assess the effectiveness of warning methods, yielding the effectiveness ranking of each warning method.

Through CRITIC-TOPSIS closeness analysis (value range: 0.206-0.839), the effectiveness rankings of seven warning methods in different driving environments were obtained. Among them, Sign.D and Sign.E exhibited the most significant warning effects across the three test environments, with the guiding speed reduction reaching up to 54.4% on sand-dust sections (100.36 km/h to 52.26 km/h, 114.8 km/h to 52.33 km/h), and their mental workload was significantly lower than that of other warning methods.

This study offers robust theoretical support for optimizing the layout of traffic facilities on expressways in sandstorm-prone regions. Specifically, it recommends prioritizing the deployment of variable speed limit signs and variable message signs, phasing out inefficient guidance signs, and optimizing the configuration of traffic facilities to significantly enhance expressway traffic management efficiency and driving safety.