Chinese Highways Research Articles

Exploring the Spatio-Temporal Trends of Geomorphological Incidents Induced by Precipitation on Chinese Highways

The spatiotemporal distribution of geomorphological incidents was examined in the present study, including the characteristics of obstruction distances and durations, by utilizing nationwide incident mitigation data and precipitation observation records from the period spanning 2019 to 2022. By comparing rainfall features over different temporal scales across various regions, the aim of the present study was to enhance the current comprehension of the patterns through which regional precipitation initiates incidents on highways by comparing rainfall characteristics over distinct temporal scales across diverse geographical areas. The findings indicate that: (1) The spatial distribution of highway incidents in China is significantly correlated with regional natural environments, predominantly concentrated in the southern parts of the country’s second and third topographical terraces. The temporal distribution closely aligns with annual and monthly precipitation patterns, with the majority of occurrences taking place from June to September. Further, notable disparities in the distribution of highway-related incidents were observed among counties across most provinces; (2) National highways experience a notably higher frequency of incidents than expressways and provincial roads, with most obstruction lengths concentrated within 1 km and durations predominantly under 3 days; (3) The probability of daily rainfall inducing highway incidents is distinctly higher than that of short-duration rainfall, with eastern and southern China experiencing significantly greater inducing precipitation volumes than other regions. The majority of areas are susceptible to incidents within a 3-day window following heavy rainfall or within 24 h after intense short-duration rainfall. Moreover, it is observed that incidents are more closely associated with extreme precipitation occurring within a single day; (4) There is a certain lag between the timing of incidents and the occurrence of extreme short-duration heavy rainfall, with the highest frequency of incidents coinciding with continuous rainfall periods of 3 to 6 days.

A Dynamic Collision Risk Assessment Model for the Traffic Flow on Expressways in Urban Agglomerations in North China

Expressways in urban agglomerations are important in connecting cities, thus attracting great attention from researchers in the expressways risk assessment. However, there is a lack of safety assessment models suitable for the characteristics of expressways in Chinese urban agglomerations, and the nature and mode of dynamic risks on Chinese highways are still unclear. Therefore, this study adopts the Adaptive Neural Fuzzy Inference System (ANFIS) and the method of decision tree, combined with data from the Beijing section of the Beijing Harbin Expressway, to model the risk of accident-prone highways in urban agglomerations. To determine the optimal model, we evaluated the model’s bias at different time intervals. In addition, key factors affecting highway safety were analyzed, providing scientific support for the risk prevention of highways in urban agglomerations in China.

Identification Method for Crash-Prone Sections of Mountain Highway under Complex Weather Conditions

Mountain highway crashes usually have a weather tendency, and the crash-prone sections show obvious weather differences. However, there were few targeted quantitative analyses of the impact of weather conditions on crash-prone sections in previous studies. Aiming at the problem that traditional identification methods ignore the difference in weather, this paper proposed the time-spatial density ratio method. The method quantified the length of the road section, the period, and the influence of different weather conditions through the time-spatial density ratio. Then the time-spatial density ratios under different weather conditions were comprehensively sorted in parallel. Finally, the risk threshold was determined according to the characteristics of the cumulative frequency curve’s double inflection points, and the crash-prone sections under each weather condition were identified. This paper evaluated the crash-prone sections of the G76 Expressway. Moreover, the crash risk situation under each weather condition was characterized through kernel density analysis. The method was compared with the cumulative frequency method, a traditional method suitable for Chinese highways with similar application conditions. The effective search index was utilized as a comparison factor. The results showed that the effective search index of the time-spatial density ratio method was more than 80% greater than that of the cumulative frequency method.

Effectiveness of Warning Piles on Driving Behavior on the Curve of Low-Grade Highway

To develop a scientific and practicable guideline for implementing warning piles on Chinese low-grade highways, it is necessary to study the effect of warning piles on driving performance in different road alignments and environments. Based on a driving simulator, this paper evaluates the effect of unilateral and bilateral warning piles on vehicle speed and lateral position on a two-lane rural highway curve with different road geometries. The results show a significant effect of bilateral warning piles on speed control, which becomes more obvious as the radius of the curve decreases and the superelevation increases. In sharp curves, vehicle speed increases rapidly in the second half of the curve, and bilateral warning piles could significantly control speed increase to prevent danger. Meanwhile, the effect of bilateral warning piles on keeping vehicles in a safer lane position is also statistically significant in the second half of the curve. With a decreasing radius and an increasing superelevation, the value of the maximum lateral position will increase. Bilateral warning piles could reduce the lateral position to keep the vehicle on a stable track. Moreover, bilateral warning piles could also perform better at night. This paper studies both unilateral and bilateral warning piles’ effects on driving behavior in different road geometries, thus providing a theoretical basis for the engineering application of warning piles.

Growth: From Microorganisms to Megacities by Vaclav Smil

Reviewed by: Growth: From Microorganisms to Megacities by Vaclav Smil Ruth Schwartz Cowan (bio) Growth: From Microorganisms to Megacities By Vaclav Smil. Cambridge, MA: MIT Press, 2019. Pp. 634. Growth: From Microorganisms to Megacities By Vaclav Smil. Cambridge, MA: MIT Press, 2019. Pp.634. Remember that kid in third grade? The one who memorized all the rivers in Africa, then made you feel like a jerk because she knew so much more than you? Or maybe that kid was you? Or me? Thankfully, we both grew out of it. Vaclav Smil did not. Smil, distinguished professor of environmental science emeritus at the University of Manitoba, is the author of 37 previous single-authored books, all focused on some aspect of pre-pandemic global environmental, economic, and social crises. Growth has a similar focus, but you won't find that out until you have plowed your way through 448 poorly organized pages containing dozens and dozens of graphs about the growth patterns of—the subtitle actually minimizes the scope of the enterprise—everything from microorganisms to megacities, plus empires and civilizations. In his preface, Smil tells us that he intends to examine growth quantitatively, looking for patterns in the data, particularly "S-shaped (sigmoid) growth curves" (p. xxi). He's a bit cagey, however, about whether all the data and S-shaped curves he intends to display will, or even should, lead to secure forecasts of future growth, or lack thereof. He cautions against "any simplistic embrace of even the best statistical fits for long-term forecasting," then in the next paragraph declares that "parts of the book are helpfully predictive" (p. xxiii). The pages of Growth are riddled with similarly ambivalent and protective statements about the ultimate meaning of the S-shaped growth patterns he describes. In excruciating detail. But before we get to that detail, a sixty-nine-page introductory chapter, as its title suggests, is intended to elucidate "Trajectories: or common patterns of growth." Unfortunately, much of the chapter will only be intelligible to readers who understand a "perfect power-law function (approximating the form f(x)=ax-k where a and k are constant)" (p. 60). A reader unfamiliar with the nuances of advanced statistics may well cower in frightful admiration, an effect (and affect) which strikes me as the grownup version of what that kid in third grade was hoping to achieve. Four substantive chapters, occupying 448 pages, follow the introduction: Nature, Energies, Artifacts, and Populations, Societies, Economies. Each chapter is divided into subsections with no rhyme and little reason; each subsection is filled with a miscellany of data analyses and charts. None ends with a concluding generalization that makes sense out of the very different growth patterns discussed. Historians of technology who might want to use Growth as a handy reference [End Page 916] work about growth patterns on such diverse subjects as the maximum thrust of jet engines or the total length of Chinese highways will need to be exceedingly careful. One graph, presumably based on data that I happen to know something about (adoption rates of household appliances in the U.S., 1900–2005, p. 294) is multiply fraudulent. Leaving aside the fact that there is no reliable national data for the period 1900–1960, the graph Smil publishes cannot be found in the source he cites. That source (for which Smil gives both the wrong date and wrong URL) contains data (and a graph) about something else altogether, and only the years 1973–2006. The mistakes just keep coming. P. Taylor et al. "Luxury or necessity?" is at www.pewresearch.org/wp-content/uploads/sites/3/2010/10/Luxury.pdf. One can compare the URL publication date in Growth (p. 605). Colleagues, you have been warned! Growth concludes with a sixty-page chapter "What Comes After Growth: or demise and continuity" and a five-page "Coda." Here Smil reveals that the growth trajectory he really cares about is the one for "high energy civilization." Unfortunately, after treating us to extended critiques of both pro-growth and limits-to-growth economists, as well as arguments against the concepts of sustainable growth and de-materialization, Smil concludes that everyone who has ever modeled the...

Analyses of the defects in highway tunnels in China

The number and length of highways in China far exceed those in other countries. Therefore, to better understand the defects that have occurred in Chinese highways that are currently in service, we collected data on the defects in 90 such tunnels. Using these data, we conducted a systematic study on the causes of such defects. Based on the characteristics thus obtained, the defects could be divided into seven categories: structural deformation, structural damage, material deterioration, water leakage, frost damage, construction defects, and others (accessory facility defects). The results reveal that lining cracks and water leakage are the most common defects in the highway tunnels of China. These tunnel defects can be categorized based on their risk, correlations, visibility, regional characteristics, and progressive nature. Human activities are the primary cause of highway tunnel defects. The treatment measures for such tunnel defects in China can be categorized as additional, repair, and replacement measures; these measures are selected based on actual requirements of addressing the defects. Lastly, corresponding preventive measures and disposal procedures are established based on the abovementioned analyses. The results of this study are expected to serve as a reference and provide significant guidance for the prevention and treatment of road tunnel defects.

Development of fatigue damage model of asphalt mixtures based on small-scale accelerated pavement test

As the primary surface type for high-grade Chinese highways, the long-term performance of asphalt pavement can affect significantly transportation efficiency. It has been confirmed that fatigue cracking is one of the major failure modes for asphalt pavement, which can cause a great reduction of asphalt pavement durability. Currently, the fatigue properties of asphalt mixtures are evaluated mainly based on traditional laboratory fatigue tests, such as bending fatigue tests and indirect tensile fatigue tests. However, none of these fatigue test methods can realistically evaluate the fatigue performance of asphalt pavement under the repeated wheel load. To resolve this issue, the model mobile load simulator (MMLS3), which is a small-scale accelerated pavement test device, was utilized to evaluate the fatigue life of six kinds of asphalt mixtures. The fatigue damage variable was defined as stiffness reduction. Based on the small-scale accelerated pavement test, a stiffness reduction model for asphalt mixtures was determined. A stiffness reduction law for asphalt mixtures during the fatigue process was proposed. The stiffness evolution process could be divided into three phases, which are the adaptation phase, the quasi-stationary phase, and the failure phase. A maximum value of the rate of stiffness reduction from the quasi-stationary phase into the failure phase was proposed as the failure threshold. Besides the fatigue life obtained from the failure criteria had a good agreement with the test results. The results from this research can be used as a theoretical reference for evaluating the fatigue life of asphalt mixtures and improving the durability of asphalt pavement.

Driving simulator study of the comparative effectiveness of monolingual and bilingual guide signs on Chinese highways

As China has become more attractive for foreigners to travel or work, some Chinese-English bilingual guide signs have been adopted on the highways for the convenience of foreign drivers. This research examined the effectiveness of Chinese-English bilingual guide signs on highways in China for drivers with different language backgrounds. The study involved three different groups of participants: Chinese (Group C), foreigners who passed the Chinese proficiency test HSK (Group FC), and foreigners without Chinese proficiency test (Group F). A driving simulator and an eye tracker were used to obtain eye movement and driving behaviour data for both monolingual and bilingual guide sign scenes. The results showed that, for Groups C and FC, their performance in the two scenes had little difference when the number of Chinese place (destination) names on the sign was 5 or less. However, the performance of Groups C and FC in the bilingual guide sign scene was worse than that in the Chinese guide sign scene when the number of place names exceeded 5. Moreover, the participants’ performance worsened as the number of place names increased for all different groups within the same scene. Thus, the threshold of the number of place names for bilingual guide signs on highways appears to be 5. Actually, the English place names on the bilingual guide signs did not have much practical effect on the drivers, since the letters of the place names were too small to be quickly seen and the translation was inaccurate.

Microscopic Congestion Detection Protocol in VANETs

Effective transportation status surveillance imposes critical challenges for the Intelligent Transportation System (ITS) design. In this paper, the microscopic congestion detection protocol (MCDP) is proposed to make the vehicle-to-vehicle (V2V) communication capable of monitoring vehicle density and identifying traffic jam. By introducing transportation control domain in the existing network protocol header, each vehicle can count its neighbors and estimate the time spacing among vehicles. MCDP provides an infrastructure-less solution to the estimate of vehicle density, flow, and average velocity in a microscopically manner. Moreover, the safety speed limit is introduced to make each vehicle calculate its time to cover the intervehicle distance, such that every vehicle is able to assess the transportation congestion by comparing with some predefined safety time threshold. Monte Carlo simulations of the MCDP over four typical Chinese highways are presented to compare the MCDP scheme with the existing Green-Shield congestion detection scheme. In addition, real road traces generated by SUMO over NS2 are utilized to show the achieved performance in terms of throughput, end-to-end delay, and packet delivery rate (PDR) in comparison to DSR and AOMDV in IEEE 802.11p and IEEE 802.11ac scenarios. On the basis of all the results, we conclude that MCDP is an inexpensive transport congestion detection technique for Vehicular Ad Hoc Networks (VANETs).

Study on the Vehicle Increase Prediction Model on Chinese Highways

The vehicle increase prediction was discussed in the article. Starting from the actual situation and the characters of vehicle increase on the highways, various factors such as the large base of vehicle amount, the increase of average income, rural vehicle amount, the enhancement of comprehensive vehicle amount and the increase phenomena of vehicle purchase by young people to impact the vehicle increase on highways were considered comprehensively, and the statistical analysis were made aiming at these factors one by one, and the impacts of these factors on the vehicle increase on highways and the concrete impacting modes were discussed, and the vehicle increase model were established and improved. By the statistical software SPSS, the regression analysis of the curve parameter estimation was made to confirm the function form of the concrete curve, and the Mathematica and Matlab were used to confirm the parameters and influences of various factors in the model by a series of data fitting, and the final model were established.

SAFETY-BASED CAPACITY ANALYSIS FOR CHINESE HIGHWAYS: A Preliminary Study

Many years of research have led to the development of theories and methodologies in roadway capacity analysis in the developed countries. However, those resources coexist with roadway design and traffic control practices in the local country, and cannot be simply transferred to China for applications. For example, the Highway Capacity Manual in the United State describes roadway capacity under ideal conditions and estimates practical capacities under prevailing conditions in the field. This capacity and the conditions for change are expected to be different on Chinese roadways as the local roadway design (lane width, curves and grades), vehicle size, and traffic mix are different. This research looks into an approach to the capacity issue different from the Highway Capacity Manual. According to the car-following principle, this paper first describes the safety criteria that affect traffic operations. Several speed schemes are subsequently discussed as they are affected by the maximum speed achievable under the local conditions. The study has shown that the effect of geometric and traffic conditions can be effectually reflected in the maximum speed adopted by the drivers. For most Chinese highways without a posted speed limit, the choice of speed by the drivers from the safety prospective is believed to have incorporated considerations of the practical driving conditions. Based on this, a condition for capacity calculation is obtained by comparing the desired vs. safety-based distance headways. The formulations of the model are mathematically sound and physically meaningful, and preliminary testing of the model is encouraging. Future research includes field data acquisition for calibration and adjustment, and model testing on Chinese highways.