Relationships between road accidents and hourly traffic flow — II. Probabilistic approach

1983 ◽  
Vol 14 (3) ◽  
pp. 138
Author(s):  
A. Cedar
1982 ◽  
Vol 14 (1) ◽  
pp. 19-34 ◽  
Author(s):  
Avishai Ceder ◽  
Moshe Livneh
Keyword(s):  

Author(s):  
Bahar Dadashova

In this paper the effect of truck traffic on road safety has been analyzed through simulation study. The main objective of the study is to quantify the effect of the decreasing average annual daily traffic of heavy duty vehicles (trucks) on road safety. As the road safety indicators the frequency road accidents is considered. The data used in the study were collected from one of the most crowded routes in Spain which connects Almeria (south-east) with Barcelona (northeast). The observed data covers year 2010 and were classified into 2 road types: dual carriageways and toll roads. The estimation was carried out using negative binomial model and Markov Chain Monte Carlo simulation. Using the estimation results new traffic scenarios were proposed where the traffic flow is assumed to change its values. A total of 33 scenarios were proposed and new accidents data were generated through MCMC sampling. The comparison of the simulated and observed accident data shows that the effect of decreasing truck traffic flow could meliorate road safety in the route. The simulation tool could be applied to evaluate the effects of freight modal shift from road to rail.DOI: http://dx.doi.org/10.4995/CIT2016.2016.4214


Author(s):  
O. V. Mayboroda ◽  
◽  
B. A. Sarymsakov ◽  

The article presents the results of the development of an integral indicator of road safety - the road safety coefficient. The value of the road safety coefficient shows how many times, at the same levels of motorization, the risk of death of a resident in road traffic (social risk) decreased/increased in comparison with the average social risk that existed in the world in the 40s of the last century, when there were no special programs on improving road safety. The use of the road safety coefficient allows you to compare the level of road safety in countries and regions with different populations and different levels of motorization. It is shown that social risk is a complex indicator, the value of which depends on the indicators of road safety at a lower level - the probability of participation of a resident in road traffic, which is equal to the value of motorization, the probability of death of a road user (transport risk), the probability of a road accident (active road safety), the intensity of road accidents (reliability of driving) and the average annual mileage of the car, the probability of death in a road accident (passive and post-accident safety). An equation is obtained that relates the value of social risk to the values of lower-level road safety indicators. The analysis of the level of road safety in Kyrgyzstan is carried out. It is shown how the condition of the traffic flow affects its average speed and the probability of road accidents. The influence of traffic flow density on its average speed and intensity of road accidents is considered. To assess the impact of the condition of a traffic flow on its average speed and road safety, the concept of the conventional density of a traffic flow is used. It is revealed that in the road conditions of Kyrgyzstan there is a critical conventional density, when exceeding it the transport risk, the probability of a road accident and the probability of death in a road accident begin to decrease rapidly with a further increase in the conventional density. The low efficiency of detection of exceeding a permitted speed when measuring the maximum speed of cars at certain points is shown. It is proposed to use the measurement of average speed on certain road sections as a means of reducing the number of drivers exceeding the speed limit.


2020 ◽  
Vol 164 ◽  
pp. 03023 ◽  
Author(s):  
Olga Makovetskaya-Abramova ◽  
Yuriy Lazarev ◽  
Marina Gravit ◽  
Svetlana Silla ◽  
Mariya Shakhova

The purpose of the study is the development of methods of identification of vehicles. These methods based on the system of identification their optical images for organization of movement and reducing the number of road accidents. There is a way of mathematical processing of signals in this method. These signals are registered with the help of optical-electronic sensors for the rapid decision-making based on computer technology. As a result, there is a confirmation of the method’s operability in real conditions. Digital signal processing lets to determine the intensity, speed and density of traffic flow automatically. At the same time, multiplicative method is a method of multidimensional analysis in a multidimensional space of numerical criteria. It divides the traffic flow by classes. This technology opens a lot of great opportunities for optimizing traffic management and helps to improve the safety of vehicles. The results of the survey are proposed for using in smart city systems.


Author(s):  
Yasser Hassan ◽  
Mohamed Sarhan ◽  
Mohsen Salehi

A speed-change lane (SCL) is an auxiliary lane added to the traveled way for the acceleration and deceleration of vehicles entering or leaving a roadway. When the length of an acceleration SCL is adequate, drivers are able to accelerate comfortably from the speed at entrance to a speed appropriate to the road, find a gap in the traffic flow, and merge in a safe and secure manner. The length of an SCL is currently determined in terms of the ramp design speed, the freeway design speed, and the acceleration rate. Embedded in these values are assumptions for the operating speed at the entrance and merging points. This study examined a probabilistic approach instead of such a deterministic approach. The main benefit of a probabilistic approach is that traffic flow characteristics are assumed to be stochastic; therefore, the outcome of a probabilistic methodology is a distribution of drivers’ acceleration distance on the SCL. The reliability-based analysis enables designers to select a specific percentile value of this distribution as a design length that better matches a certain situation and avoids unnecessary extra construction costs. This paper presents analytical and simulation models for the application of the reliability approach, with all parameters based on recently collected field data. Even though the presented model should be superior to the deterministic model adopted in current design guides, additional enhancements are recommended for a full reliability-based, safety-explicit design model.


2013 ◽  
Author(s):  
◽  
Oscar M. Kunene

An increase in road traffic, poor road conditions and high numbers of road accidents are major challenges at the Port of Durban. Roads are considered as the most important transport mode at the Port of Durban. Road transport has taken almost 80% of the import and export cargo while railway transport is left with approximately 20%. It is estimated that 75 million lives in the world will be lost and 750 million people injured in road accidents in the first half of the 21th century. The Port of Durban is an important vehicle for facilitating economic growth of local, regional and national industries. For the Port to maintain global competitiveness with the current trend of globalization, it has to ensure that roads are well maintained, safe and have a smooth traffic flow with no delays. This study provides an overview of the road infrastructure within the Port of Durban in relation to road condition, safety, law enforcement and traffic. Existing and ongoing studies conducted in South Africa and abroad form part of the literature review. This study identifies factors that are affecting the condition of road infrastructure such as growth of container cargo, an increase in the dimension and weight of trucks, transport deregulation, port layout and handling equipments. Deregulation of road transport over the past years has resulted in an 80:20 split between road and rail transport putting more pressure on roads. Cost and time are the major deciding factors in the freight industry. Most customers prefer to use road transport due to the lower cost and reduced time compared to rail transport. There are eight major roads within the Port that connect the South, West and North of eThekwini Municipality namely Bayhead, Quayside, Maydon, Rick Turner, Wisely, South Coast, Bluff and Iran Roads. Asset verification and assessment of the condition of the existing eight major roads found that Quayside Road is in a better condition compared to the other roads. Maydon and South Coast Roads are low rated roads which are in a poor condition. Identification and assessment of the condition of 210 000m² of asphalt paved areas which included minor roads within the Port of Durban was also conducted. Most paved areas and roads fall under D (fair) category which is reasonable but maintenance work may be required within six months. Comparison between the condition of the eight major roads within the Port and outside the Port was investigated. The findings indicate that sections of roads outside the Port are in a better condition than sections within the Port. Traffic counts were conducted in order to determine the utilization of the existing eight major roads. Bayhead and South Coast Road are highly utilized roads. Road accident reports and death reports were analyzed on these roads. Most of the road accidents take place on South Coast Road. A questionnaire survey was conducted, targeting road users who travel on these roads within the Port. Feedback was obtained on the status of road conditions, safety and traffic within the Port of Durban. Findings of this survey revealed that most of the respondents don’t know where to report road defect/s within the Port. Approximately 37.5% of the road users felt not safe to drive on roads within the Port especially on South Coast Road. A high percentage of people (93%) witnessed accidents on these roads. Traffic signals within the Port are maintained by eThekwini Municipality and are very often non-functional. When road signs need to be repaired or replaced, it takes longer than expected. Also, there are limited parking areas around the Port resulting in trucks parking closer to the premises while waiting to collect or deliver cargo. This causes major traffic congestion, for example, on Maydon Road where most trucks park on the side of the road. Recommendations include assessment guidelines that could improve road condition, safety and traffic flow. Areas to be improved with regard to road infrastructure are also highlighted.


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