Analysis of speed characteristics for rural two-lane roads: A field study from Minoufiya Governorate, Egypt (original) (raw)
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Impact of highway geometry and posted speed on operating speed at multi-lane highways in Egypt
Journal of Advanced Research, 2013
The paper presents an analysis of roadway factors and posted speed limits that affect the operating speed at multi-lane highways in Egypt. Field data on multi-lane highways in Egypt are used in this investigation. The analysis considers two categories of highways. The first consists of two desert roads (Cairo-Alexandria and Cairo-Ismailia desert roads) and the second consists of two agricultural roads (Cairo-Alexandria and Tanta-Damietta agricultural roads). The paper includes three separate relevant analyses. The first analysis uses the regression models to investigate the relationships between operating speed (V 85 ) as dependent variable, and roadway factors and posted speed as independent variables. The road factors are lane width, shoulder width, pavement width, median width, number of lanes in each direction, and existence of side access along each section. The second analysis uses the Artificial Neural Network (ANN) to explore the previous relationships while the third one examines the suitability of the posted speed limits on the roads under study. It is found that the ANN modeling gives the best model for predicting the operating speed and the most influential variables on V 85 are the pavement width, followed by the median width and the existence of side access along section. It is also found that the posted speed limit has a very small effect on the operating speed due to the bad behavior of drivers in Egypt. These results are so important for controlling V 85 on multi-lane rural highways in Egypt.
Toward an operating speed profile model for rural two-lane roads in Egypt
2016
The geometric design, especially the horizontal and vertical alignments, of rural two-lane highway facilities is considered one of the most important factors affecting the quality of traffic service and safety. A consistent highway geometric design is defined to be one that conforms to the driver's expectations. In order to calculate the main measures of design consistency, an accurate operating speed profile model for road alignment is needed. Studies have shown that operating speed models are country dependent due to varying demographics, driver attitudes, habits, etc. This paper develops a speed profile model for two-lane rural roads in Egypt. This includes the development of operating speed models for horizontal curves and tangents, as well as the study of the characteristics and relationships between acceleration and deceleration rates before and after horizontal curves. The study uses a desert rural two-lane, two-way road sections that connect the city of Sohag with the city of Hurghada, in Upper Egypt. All geometric characteristics were obtained from highway authority. Speed data regarding individual drivers traveling on selected two-lane rural road sections were sampled using an on-board GPS system. The study confirms the finding in previous research that curvature is the most important factor in determining the speed on horizontal curves. Moreover, tangent length is the most important factor in determining operating speeds at tangents. The acceleration and deceleration characteristics were derived to gain an understanding of the behavior of individual vehicles traveling through curves of varying radii and lengths as well as preceding tangent length. Several operating speed models were developed for tangents and curves as well as for acceleration and deceleration rates. Incredibly effective, these models can be used for design consistency evaluations. ScienceDirect j o urna l h om epag e: www.elsevier.com /locate/jtte j o u r n a l o f t r a f fi c a n d t r a n s p o r t a t i o n e n g i n e e r i n g (e n g l i s h e d i t i o n) 2 0 1 6 ; 3 (1) : 8 2 e8 8
Operating speed models for two-lane rural roads in Pakistan
Canadian Journal of Civil Engineering, 2008
One of the suitable techniques used to improve safety on roads is to check the consistency of geometric design. The concept of design consistency has emerged worldwide, but no research has been found to date on design consistency in Pakistan. The most common parameter for the evaluation of design consistency is operating speed. Several models have been developed to predict operating speed on two-lane rural roads. However, these models were based on spot speed data collected through traditional speed measuring devices. This study uses continuous speed profile data collected using a vehicle equipped with a VBox (a global positioning system based device). Eleven test sections were selected in two provinces of Pakistan (i.e., Sindh and Balochistan). Driver behavior is also studied in the present research. Models were developed for prediction of operating speed on horizontal curves and on tangents. Validation of the developed models shows compatibility with the experimental data; hence, ...
This study presents the development of operating speed models for daytime and night-time conditions for highways in Egypt based on a study of 58 horizontal curves at different sites on rural multilane roads. In each horizontal curve, spot speeds at each horizontal curve and tangents between them were collected during the day and night at five points. Spot speeds were collected at the middle of first tangent, point of curve, middle of curve, point of tangent and the middle of second tangent. In the operating speed models, the radius of the horizontal curve was used to estimate the operating speed. The speed models determined that the operating speed correlated with the radius of the horizontal curve. Statistical tests were used to compare daytime and nighttime speeds at the midpoint of each horizontal curve. The comparison reveals that there is no statistical difference between daytime and nighttime speeds at the midpoint of the horizontal curves. Another test was done to investigate the design consistency of the horizontal curves. Comparison between speeds at the main points of the horizontal curve was made. Differences between speeds at point of curve, middle of curve and point of tangent were examined within the tested horizontal curves using ANOVA. The results of ANOVA test for horizontal curves in each group showed that there is no significant difference in speeds between each two successive points within the horizontal curve.
Speed Behavior of Heterogeneous Traffic on Two-Lane Rural Roads in Malaysia
Sustainability
Highway geometry is a significant factor that affects the efficiency and safety of highway systems. The present study aims to investigate the speed behavior of various vehicle classes on the horizontal alignment of two-lane rural roads. An automatic data collection system based on a pressure sensor was employed to collect the speed of each individual vehicle, vehicle type, and headway at seven sites in each travel direction. The 85th percentile speed under free-flow conditions was used to observe the relationship between the operating speeds of various vehicle classes at consecutive curve points and the effect of the travel direction, time of day, and curve radius on the operating speed of the vehicle. A one-way ANOVA was employed to evaluate whether there is a significant difference in speed on horizontal curves. Then, a Tukey post hoc test was used to assess the significance of the difference in speed across four classes of vehicles. The results revealed that the horizontal curve ...
Evaluation of performance measures for rural two-lane roads in Egypt
Alexandria Engineering Journal, 2011
This paper presents an empirical evaluation of the relationship between operational performance and platooning phenomenon in rural two-lane roads in Egypt. Seven performance measures and three platooning variables were defined and calculated for eight study sites using traffic data from roads in Minoufiya governorate, Egypt. Using graphical and statistical analyses, the associations between the performance measures and the platooning variables were examined. The results showed that the follower density performance measure was found to have the strongest correlations to platooning variables. Among the platooning variables investigated, traffic flow in the direction of travel has the highest correlations with performance measures. The study demonstrated that the relationship between follower density and traffic flow is better described by a quadratic form. Finally, threshold values for different levels-of-service were proposed. This might help traffic engineers, in Egypt, to evaluate operational performance using criteria that reflect the local conditions of the area under study.
This paper presents an analysis into traffic characteristics on rural multi-lane highways. Empirical data from study sites on Cairo-Aswan agriculture four-lane divided highway were used in this investigation. Four separate however relevant analyses are presented in this paper. The first analysis investigates the impact of lane position (Median Lane (ML), Shoulder Lane (SL)) on Average Travel Speed (ATS). The second analysis looks at the relationship between ATS and different traffic characteristics. The third analysis examines the impact of lane position on traffic stream relationships. The fourth and last analysis inspects the impact of lane position and traffic level on headway characteristics. It was found that the lane position has a significant impact on ATS. The best model that shows the relationship between ATS and traffic characteristics include density, percentage of heavy vehicles and lane position variables. The lane position also has a significant impact on traffic stream relationships. Finally lane position and traffic level have a considerable impact on headway characteristics.
Speed Factors on Two-Lane Rural Highways in Free-Flow Conditions
Transportation Research Record, 2005
The mean free-flow speed and its variability across drivers are considered important safety factors. Despite a large body of past research on operating speeds, there is still much to learn about the factors of free-flow speeds, especially on tangent segments of two-lane rural highways. The roadway factors of speed dispersion across drivers are largely unknown. Also, the use of the entire free-flow speed distribution suggested by other authors has not been yet addressed. Consequently, the existing models are not aimed to evaluate the speed variability at a site.
Analyzing Drivers’ Speed Behavior on Various Roads in Baghdad City
Engineering and Technology Journal
The multi-lanes and two-lane roads witnessed more frequent speed limits than local residential roads. The age factor is the more correlated factor to exceeding speed limits. This study recommends the provision of public transportation instead of private means of transport. This study investigates the driver behavior of a certain number of drivers using a questionnaire method. The questionnaire contains a part of drivers' demographics, including age, gender, and the type of transportation most used by the drivers. It was divided into three parts. Each part deals with a specific type of road in Baghdad City: multi-lane, two-lane, and local. The questions were about the number of times they drove the vehicle on each type of road, the speed at which they drove the vehicle and did not cause accidents, the distance traveled during the last week on each type of road, and the number of times the speed limit was exceeded. The most prominent reasons for increasing the speed of drivers were also indicated, and solutions were suggested to reduce the speed of drivers. The results show that the driver's age was considered an important factor in the driver's behavior. It was found that the older the driver, the more committed he was to the proposed speed limits for each type of road. In addition, spreading public awareness about speed reduction to reduce violations and accidents is vital.