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The real-time traffic conflict risk warning system (RTCRWS) is proposed as a new proactive crash prevention and control strategy for intersections designed to reduce traffic on the main road to rural unsignalized intersections when a vehicle enters the access roads. This study aims at evaluating the effectiveness of the RTCRWS with different locations based on a driving simulation experiment. In this study, four types of the RTCRWS installation location schemes (i.e., no installation, 50m/100m/150m away from the unsignalized intersection) are designed. Twenty-two experienced drivers participated in the driving simulation experiment, and seven evaluating indicators representing driving behavior data are proposed. Two methods to analyze the data are applied: (1) descriptive analysis of driving behavior characteristics different location schemes of the RTCRWS and (2) entropy weight-fuzzy comprehensive evaluation of the RTCRWS. The results show that the RTCRWS has a significant effect on slowing vehicles when approaching the rural unsignalized intersections. If the location of the RTCRWS is 50m, 100m, and 150m from the intersection, the comprehensive score of fuzzy evaluation is 75.82, 74.91, and 77.22, respectively, which implies that the scheme with the RTCRWS 150m ahead of the intersection is the most effective., Author(s): Chengyu Hu [1,2]; Changan Xiong [2,3]; Fengxiang Guo (corresponding author) [3]; Jaeyoung Lee [4]; Wenchen Yang [2]; Zhongyin Guo [1] 1. Introduction In recent years, with the increasing number [...]

Work zone crossover is an important area in highway reconstruction and expansion projects because it profoundly impacts the traffic safety and efficiency of the construction sites. This research sets the different median opening widths in the driving simulation experiment, collects the vehicle control signal parameters during entrance by-pass and exit by-pass, and analyzes the driving characteristics in these sections. Comparison of the driving features between the simulation experiment and the actual driving under the same median width has been also made. We should set the median width separately because the results show that driving behaviors significantly differ between entrance by-pass and exit by-pass. When the median opening width is 70m, the driving simulation experiment and actual driving characteristics are quite different. However, both show that driving factors of the entrance and exit by-pass are not the same. When there are two lanes in the traffic control zone and the speed limit is 60km/h, we should set the median width at 90m to ensure transportation safety., Author(s): Lu Lv [1]; Yanting Sheng [2]; Cancan Song [1]; Yongqing Li [3]; Zhongyin Guo (corresponding author) [1] 1. Introduction Freeway work zone is a hazard to workers, transportation departments, [...]

The accumulation and melting process of snow and ice contamination was simulated in an advanced environmental cabin. The pavement surface condition was monitored using the Vaisala mobile detector, and the friction coefficient between the tire and pavement was measured with the T2GO friction tester. The dynamic variation of the friction coefficient and its deterioration mechanism under various conditions were analyzed. Results show that after a thin ice layer develops on the surface of the coarse aggregate, the cohesion friction component decreases rapidly. Then, as the ice coverage widens, the hysteresis friction component decreases considerably. When the coverage rate of the ice layer reaches 100% and the thickness reaches 0.2–0.3 mm, the friction coefficient decreases to 0.2. In the process of snow accumulation, the friction coefficient is maintained at 0.43–0.45. As the snow layer is soft and easy to compact, the tire rubber can be embedded onto it; even if the thickness can sufficiently cover the macrotexture of the pavement, the hysteresis friction component can be maintained at a high level. In the early stage of snow melting, an ice layer forms on the snow layer's surface, which reduces the friction coefficient to 0.2. [ABSTRACT FROM AUTHOR]

Driving comfort is crucial for tunnel safety because tunnel sections on freeways often introduce significant environmental changes that can compromise comfort and increase the risk of traffic accidents. This study aimed to quantitatively evaluate the driving comfort in tunnel sections and its implications for safety management. Four indicators were used to assess the driving comfort: heart rate growth rate (Hrgr), skin conductance response (SCR), speed, and acceleration. The CRITIC weighting method was employed to calculate a quantitative driving comfort score, and the presence and severity of discomfort were used to evaluate the safety of each tunnel area. In addition, the evaluation was based on a naturalistic test consisting of Hrgr, SCR, speed, and acceleration data. A total of 32 participants were recruited based on a web-based questionnaire screening process, after which they were tested while driving through 30 tunnel sections on the roadway. These 30 tunnels included 14 short (< 500 m), 12 medium (500–1,000 m), and 4 long (1,000–3,000 m) tunnels. The results revealed that the four selected indicators exhibited minimal multicollinearity and effectively captured the driving comfort. Among the indicators, SCR had the most significant contribution to the driving comfort score. Most drivers did not experience substantial discomfort while driving through tunnels. The area where drivers were most susceptible to discomfort was the middle zones of tunnels. However, drivers were more likely to experience strong discomfort in the outside exit, entrance, and middle zones of short, medium, and long tunnels, respectively. This study provides a comprehensive set of safety evaluation methods for tunnel sections on freeways, with a focus on quantifying the driving comfort. The findings provide theoretical support for freeway management personnel in implementing personalized controls in different tunnel areas with the aim of enhancing tunnel safety and mitigating the occurrence of traffic accidents. [ABSTRACT FROM AUTHOR]

Driving simulation is an efficient, safe, and data-collection-friendly method to examine driving behavior in a controlled environment. However, the validity of a driving simulator is inconsistent when the type of the driving simulator or the driving scenario is different. The purpose of this research is to verify driving simulator validity in driving behavior research in work zones. A field experiment and a corresponding simulation experiment were conducted to collect behavioral data. Indicators such as speed, car-following distance, and reaction delay time were chosen to examine the absolute and relative validity of the driving simulator. In particular, a survival analysis method was proposed in this research to examine the validity of reaction delay time. The result indicates the following: (1) most indicators are valid in driving behavior research in the work zone. For example, spot speed, car-following distance, headway, and reaction delay time show absolute validity. (2) Standard deviation of the car-following distance shows relative validity. Consistent with previous researches, some driving behaviors appear to be more aggressive in the simulation environment., 1. Introduction Driving simulation has been increasingly popular in transportation research because of its efficiency, safety, and controllability. By using driving simulation, researchers can design a specific driving scenario, conduct [...]

Crash risk prediction plays a pivotal role in traffic management and infrastructure optimization. Previous research has studied the relationship between crashes and multiple factors using statistical methods. As both drivers' attention and environmental complexity substantially affect traffic safety, this article presents a novel method to predict crash risk proactively by combining these two interactive factors. More than 200 high-risk zones and 300 noncrash zones were screened out through social media data. Corresponding environmental information was collected using the street view map. Spectral saliency mapping was applied to depict the driver's attention distribution toward images. A DeepLabV3 pretrained network was implemented to label the semantic features in the environment. A featured vector was then constructed by fuzing the visual attention model and image semantics. The gradient boosting decision tree algorithm was applied to analyze the relationship between the multitype crash data and featured vectors. The results showed that the accuracy of the proposed method for detecting different types of crashes was over 0.81. Dynamic objects are the most substantial factors that affect crash possibility and categories. Traffic signals are vulnerable to drivers' attention, which may be easily overlooked. The proposed method provides new insights into understanding traffic crash risk, which can help us predict different types of crashes more effectively. [ABSTRACT FROM AUTHOR]

Incidents may arise in road tunnels, in particular at the tunnel entrance and exit. Investigation conducted in the road tunnels in the provinces of Guizhou and Yunnan in China showed that the concrete pavement surface skid resistance decreased rapidly inside the tunnels and was significantly different from that outside the tunnels. Pavement surface skid resistance is one of the most important factors that affect travel safety, in particular wet weather skidding accidents. Countermeasures are necessary to enhance the skid resistance on concrete pavements in tunnels. The writers made an effort to investigate possible pavement surfaces to provide long- lasting skid resistance, including porous concrete surface and open graded friction course (OGFC) surface. Porous concrete was paved directly on the regular concrete pavement and OGFC was paved on the existing surface of concrete pavement to provide sufficient skid resistance. Accelerated abrasion devices have been developed to evaluate the skid resistances of the porous concrete and OGFC, respectively. Regular asphalt materials will bum easily and emit toxic gas in fire, which may reduce the survival rate for tunnel users involved in fire accidents. Fire-retardant asphalt has been developed to reduce the tendency of asphalt materials to burn and reduce emission. CE Database subject headings: Tunnels; Skid resistance; Concrete pavements; Porous materials; Fire resistance.

Operating speed is a critical indicator for road alignment consistency design and safety evaluation. Although extensive studies have been conducted on operating speed prediction, few models can finish practical continuous prediction at each point along alignment on multilane highways. This study proposes a novel method to estimate the operating speed for multilane highways in China from the aspect of the three-dimensional alignment combination. Operating speed data collected in field experiments on 304 different alignment combination sections are detected by means of Global Positioning System. First, the alignment comprehensive index (ACI) is designed and introduced to describe the function accounting for alignment continuity and driving safety. The variables used in ACI include horizontal curve radius, change rate of curvature, deflection angle of curve, grade, and lane width. Second, the influence range of front and rear alignment on speed is determined on the basis of drivers&apos; fixation range and dynamical properties of vehicles. Furthermore, a prediction model based on exponential relationships between road alignment and speeds is designed to predict the speed of passenger cars and trucks. Finally, three common criteria are utilized to evaluate the effectiveness of the prediction models. The results indicate that the prediction models outperform the other two operating speed models for their higher prediction accuracy., 1. Introduction Human-orient and safety supremacy are currently the new guidance during the period of highway construction. The traditional design speed-based alignment design approach usually only specifies the minimum value [...]