The Evaluation Analysis of Design Code About the Road Design of longitudinal gradient in the Mountain Road

Abstract

Abstract. In recent years the highway develops rapidly in China, by the end of 2014, the total mileage of China's highway has reached 4.3 million kilometers. Among those, the total mileages of the speedway broke through the bottleneck of 110 thousand kilometers -which ranks the first in the world. With the fast development of basic traffic construction, the problem of safety has become more and more significant. However, some highway (especially, the long longitudinal gradient in the mountain area) has the high accident rate, which caused serious casualties and a great loss of social economy. Aim to this condition, the roads with high accident rate were investigated and analyzed in this paper and the reasons caused accident were studied. The research shows that, besides the carelessness of drivers and the deficiency of the vehicles, the phenomenon of continuous long down design was the same character among those mountain roads .Although those design were not beyond the limiting value, but the maximum longitudinal slope length and slope values almost reach the specification limit frequently, so the rationality of the road design regulations on continuous long down in the mountain road is also worthy of consideration. In this paper, based on the project case of the highway from Shizhong to HeXi in FuJian province, the operational safety of this road was estimated based on the security analysis method of USA, the study shows that, the highway's parameter on the longitudinal gradient is in accordance with Chinese design regulations, but according to the, the danger coefficient is very high in this section of accident highway, which dues to frequently traffic accident. In conclusion, the design regulations of the highway should be improved gradually to assure the traffic safety of highway.

Models of Analysis of Credible Deviation from Speed Limits on Two‐Lane Roads of Bosnia and Herzegovina

“…e main reason for exceeding speed limits, by some authors, refers to the credibility of set speed limits because drivers do not consider them realistic [18][19][20]. However, some authors have investigated the functional dependence of speed, length of individual geometric elements of the road, radius of curvature, transverse/longitudinal gradient, and traffic accidents [21][22][23][24]. Also, the research presents the problem of reducing speed due to the geometric characteristics of the road.…”

“…In the analysis of the Bayesian network for predicting the probability of the influence of traffic and road factors on the occurrence of traffic accidents, the following are especially emphasized: vehicle speed, horizontal curve radius, vehicle type, adhesion coefficient, and longitudinal slope [23]. Also, the results of a study [24] show that the continuous use of several limit indexes and the excessive average slope of long and steep sections of roads were one of the major causes of frequent 2 Complexity accidents on a section of HeXi road in China. In their study, Silvano et al assessed the impact of technical and exploitation characteristics of the road and changes in speed limits on the speed of free traffic flow using an extensive dataset of urban roads [28].…”

Ranking Road Sections Based on MCDM Model: New Improved Fuzzy SWARA (IMF SWARA)

“…However, some authors have investigated the functional dependence of speed, length of individual geometric road elements, radius of curvature of transverse/longitudinal slopes, and traffic accidents [9][10][11][12]. Additionally, in some research the problem of reducing speed due to geometric road characteristics arises.…”

“…Using the Bayesian network analysis for predicting the probability of the influence of traffic and road factors on the occurrence of traffic accidents, it is especially emphasized that vehicle speed, horizontal curve radius, vehicle type, adhesion coefficient, and longitudinal slope are important factors [11]. Additionally, the results of the study [12] show that the continuous use of several boundary indices and the excessive average gradient of long and steep road sections are some of the main causes of frequent accidents on the Hexi section.…”

Accident analysis of long and steep longitudinal highway slopes based on multi-source data under the background of Internet of Things

“…Wen-bin [5] established traffic simulation models with different actual loading rates and slope lengths through Vissim, and ultimately verified them during the renovation of the long and steep slope of the Expressway. Zheng [6] used the American safety analysis method to estimate the operational safety of long longitudinal slope highways in mountainous areas. The study showed that although the continuous long downhill of these mountain roads did not exceed the limit value, the maximum longitudinal slope length and slope value almost often reached the standard limit.…”