scholarly journals Impact of Horizontal Curves and Percentage of Heavy Vehicles on Right Lane Capacity at Multi-lane Highways

2017 ◽  
Vol 29 (3) ◽  
pp. 299-309
Author(s):  
Ahmed Mohamed Semeida
Keyword(s):  
Heavy Vehicles ◽  
Highway Design ◽  
Horizontal Curves ◽  
Traffic Characteristics ◽  
Capacity Loss ◽  
Traditional Procedure ◽  
Lane Width ◽  
Road Geometry ◽  
Traffic Composition ◽  
The Right

In the present research, the influence of road geometric properties and traffic characteristics on the right lane capacity value is explored for horizontal curves. The non-traditional procedure (artificial neural networks - ANNs), is adopted for modelling. The research utilizes 78 horizontal curves that provide the traffic and road geometry data, of which55 curves are classified as four-lane and the rest as six-lane ones. Two types of models are introduced to explore the right lane capacity as capacity at curves, and the capacity loss between curves and tangents. The results show that, for horizontal curves, the most effective variables affecting both road types are the percentage of heavy vehicles in traffic composition (HV) followed by radius of curve (R), and the lane width (LW). Furthermore, the capacity loss is also highly affected by R followed by HV. The derived outcomes present a remarkable move towards the beginning of an Egyptian highway design guide.

scholarly journals Determination of Level of Service (LOS) on Different Roads in Kuching Area (A Case study)

2009 ◽  
Vol 1 (1) ◽  
pp. 1-6
Author(s):  
Chen K.C. ◽  
Larry S.T.
Keyword(s):  
Traffic Congestion ◽  
Urban Areas ◽  
Qualitative Assessment ◽  
Level Of Service ◽  
Heavy Vehicles ◽  
Traffic Light ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Lane Width ◽  
Traffic Composition

The concept of Level of Service (LOS) is originated from the Highway Capacity Manual (HCM). LOS is a qualitative assessment of the operational performance of a roadway facility based on quantitative performance measures. Many transportation infrastructure funding decisions are based on LOS analysis, and LOS designations are intended to represent user-perceived quality of service. This study has been carried out to determine the LOS on different roads. The profile of study area is in Kuching, Sarawak where five roads with different characteristics and posted speed of urban multilane with 80km/hr and 70km/hr, suburban two-lane two-way with 90 km/hr and 80km/hr had been selected for the studies. Substantial numbers of inputs are required for the LOS analysis and determination based on HCM procedures. These inputs are: a long list of traffic volume collected in different peak hours; traffic composition such as proportion of heavy vehicles in traffic; geometric characteristics such as number of lanes, lane width, shoulder width, and approach grades. Results of the study showed that LOS in the urban multilane is still in satisfactory range with LOS ranging from C to D except for most of the traffic congestion cases in urban multilane at the traffic light junctions and roundabouts. However, LOS in the suburban two-lane two-way is only satisfying in the range of LOS E; hence multilane should be introduced in such cases. Recommendations such as to provide various or multitude modes of transportation needs should be introduced in urban area. Furthermore, a suitable and efficient hierarchy in road system should be provided in suburban areas before turning into urban areas.

Safety at Curves and Road Geometry Standards in Some European Countries

1996 ◽  
Vol 1523 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Thierry Brenac
Keyword(s):  
Urban Areas ◽  
National Standards ◽  
European Countries ◽  
Design Standards ◽  
The Road ◽  
Horizontal Curves ◽  
Road Design ◽  
Road Geometry ◽  
Design Speed ◽  
Curve Geometry

This paper deals with safety at horizontal curves on two-lane roads outside urban areas and the way the road design standards of different European countries account for this safety aspect. After a review of some research results, the main aspects of curve geometry and the curve's place in the horizontal alignment are analyzed. The main conclusions are that the traditional design speed approach is insufficient and that formal complementary rules in road design standards, especially to improve compatibility between successive elements of the alignment, must be introduced. If such complementary rules already exist in some national standards, they are neither frequent nor homogeneous throughout the different countries, and it seems that they are not based on sufficiently developed knowledge.

scholarly journals Speed Models for Motorcycle Riders for Two-lane Rural Roads

2021 ◽  
Vol 17 ◽  
pp. 595-603
Author(s):  
Panagiotis Lemonakis ◽  
George Botzoris ◽  
Athanasios Galanis ◽  
Nikolaos Eliou
Keyword(s):  
Prediction Models ◽  
Flow Speed ◽  
Operating Speed ◽  
Rural Roads ◽  
The Road ◽  
Horizontal Curves ◽  
Road Geometry ◽  
Speed Prediction ◽  
The Subject ◽  
On The Road

The development of operating speed models has been the subject of numerous research studies in the past. Most of them present models that aim to predict free-flow speed in conjunction with the road geometry at the curved road sections considering various geometric parameters e.g., radius, length, preceding tangent, deflection angle. The developed models seldomly take into account the operating speed profiles of motorcycle riders and hence no significant efforts have been put so far to associate the geometric characteristics of a road segment with the speed behavior of motorcycle riders. The dominance of 4-wheel vehicles on the road network led the researchers to focus explicitly on the development of speed prediction models for passenger cars, vans, pickups, and trucks. However, although the motorcycle fleet represents only a small proportion of the total traffic volume motorcycle riders are over-represented in traffic accidents especially those that occur on horizontal curves. Since operating speed has been thoroughly documented as the most significant precipitating factor of vehicular accidents, the study of motorcycle rider's speed behavior approaching horizontal curves is of paramount importance. The subject of the present paper is the development of speed prediction models for motorcycle riders traveling on two-lane rural roads. The model was the result of the execution of field measurements under naturalistic conditions with the use of an instrumented motorcycle conducted by experienced motorcycle riders under different lighting conditions. The implemented methodology to determine the most efficient model evaluates a series of road geometry parameters through a comprehensive literature review excluding those with an insignificant impact to the magnitude of the operating speeds in order to establish simple and handy models.

scholarly journals Studying the effect of spiral curves and intersection angle, on the accident ratios in two-lane rural highways in Iran

2013 ◽  
Vol 25 (4) ◽  
pp. 343-348 ◽  
Author(s):  
Mohammad Hossain Jalal Kamali ◽  
Mohammad Saeed Monajjem ◽  
Mohammad Sadegh Ayubirad
Keyword(s):  
Transportation Engineering ◽  
Intersection Angle ◽  
Highway Design ◽  
Rural Highways ◽  
Horizontal Curves ◽  
Accident Rates

Safety in highways is one of the most important subjects in Transportation Engineering. Increasing rate of vehicles and the needs to design or geometrically modifying the highways, emphasized on the safe-designing of the roadways more than before. Between the constructive components of the highway, horizontal curves due to the more occurrences of accidents are of great importance. The American ministry of highway and transportation introduced the software IHSDM, with variant capabilities, to predict accidents. In this research, five types of curves (simple circle curve and clothoid-circle-clothoid) at different intersection angles were designed, and accident rates based on the standard specifications on each curve was predicted by using the IHSDM, and the results are compared with each other. Finally, by processing the curves of accident rates versus the curves types and intersection angle, and comparing them with each other, the necessity of using spiral curves in the highway design is emphasized.

Analysing the Performance of a Fuzzy Lane Changing Model Using Data Mining

2015 ◽  
pp. 1540-1566
Author(s):  
Sara Moridpour
Keyword(s):  
Traffic Safety ◽  
Traffic Simulation ◽  
Heavy Traffic ◽  
Heavy Vehicle ◽  
Heavy Vehicles ◽  
Passenger Cars ◽  
Lane Changing ◽  
Microscopic Traffic Simulation ◽  
Traffic Characteristics ◽  
Using Data

Heavy vehicles have substantial impact on traffic flow particularly during heavy traffic conditions. Large amount of heavy vehicle lane changing manoeuvres may increase the number of traffic accidents and therefore reduce the freeway safety. Improving road capacity and enhancing traffic safety on freeways has been the motivation to establish heavy vehicle lane restriction strategies to reduce the interaction between heavy vehicles and passenger cars. In previous studies, different heavy vehicle lane restriction strategies have been evaluated using microscopic traffic simulation packages. Microscopic traffic simulation packages generally use a common model to estimate the lane changing of heavy vehicles and passenger cars. The common lane changing models ignore the differences exist in the lane changing behaviour of heavy vehicle and passenger car drivers. An exclusive fuzzy lane changing model for heavy vehicles is developed and presented in this chapter. This fuzzy model can increase the accuracy of simulation models in estimating the macroscopic and microscopic traffic characteristics. The results of this chapter shows that using an exclusive lane changing model for heavy vehicles, results in more reliable evaluation of lane restriction strategies.

scholarly journals Quantifying the Effects of Visual Road Information on Drivers’ Speed Choices to Promote Self-Explaining Roads

2020 ◽  
Vol 17 (7) ◽  
pp. 2437
Author(s):  
Yuting Qin ◽  
Yuren Chen ◽  
Kunhui Lin
Keyword(s):  
Field Experiments ◽  
Prediction Models ◽  
Semantic Segmentation ◽  
Qualitative And Quantitative ◽  
Road Design ◽  
Driving Speed ◽  
Road Geometry ◽  
Controlling Variables ◽  
The Right ◽  
Road Characteristics

Roads should deliver appropriate information to drivers and thus induce safer driving behavior. This concept is also known as “self-explaining roads” (SERs). Previous studies have demonstrated that understanding how road characteristics affect drivers’ speed choices is the key to SERs. Thus, in order to reduce traffic casualties via engineering methods, this study aimed to establish a speed decision model based on visual road information and to propose an innovative method of SER design. It was assumed that driving speed is determined by road geometry and modified by the environment. Lane fitting and image semantic segmentation techniques were used to extract road features. Field experiments were conducted in Tibet, China, and 1375 typical road scenarios were picked out. By controlling variables, the driving speed stimulated by each piece of information was evaluated. Prediction models for geometry-determined speed and environment-modified speed were built using the random forest algorithm and convolutional neural network. Results showed that the curvature of the right boundary in “near scene” and “middle scene”, and the density of roadside greenery and residences play an important role in regulating driving speed. The findings of this research could provide qualitative and quantitative suggestions for the optimization of road design that would guide drivers to choose more reasonable driving speeds.

Impact of heavy vehicles on surrounding traffic characteristics

2014 ◽  
Vol 49 (4) ◽  
pp. 535-552 ◽  
Author(s):  
Sara Moridpour ◽  
Ehsan Mazloumi ◽  
Mahmoud Mesbah
Keyword(s):  
Heavy Vehicles ◽  
Traffic Characteristics

Establishing highway horizontal alignment to maximize design consistency

2007 ◽  
Vol 34 (9) ◽  
pp. 1159-1168 ◽  
Author(s):  
Said M Easa ◽  
Atif Mehmood
Keyword(s):  
Geometric Features ◽  
Trial And Error ◽  
Highway Design ◽  
Rural Highways ◽  
Physical Constraints ◽  
Horizontal Alignment ◽  
Horizontal Curves ◽  
Decision Variables ◽  
Acceleration And Deceleration ◽  
Design Consistency

Highway design consistency is one of the important criteria in selecting the geometric features of proposed or existing alignments of two-lane rural highways. Operating-speed (OS) profile models have been used to evaluate design consistency by trial and error. For a proposed new highway, however, there may be geometric and physical constraints, and selection of these elements by trial and error to achieve optimal design consistency would be difficult, if not impossible. This paper presents an optimization model that establishes highway horizontal alignment to achieve maximum design consistency based on the OS profile. The decision variables of the model include radius of horizontal curves, spiral curve lengths, length of speed-change (SC) segments, and acceleration and deceleration rates. The objective function of the model minimizes the mean OS difference or the maximum OS difference for successive geometric features along the highway section. Application examples and sensitivity analysis are presented to illustrate the capabilities of the model in evaluating improvement strategies and to ensure that the model produces sound optimum alignments. The proposed model, which complements existing optimization models that mainly address highway construction cost, should be of interest to highway practitioners and engineers.Key words: design consistency, highway, geometric, horizontal alignment, optimization modeling, speed profile.

Influence of Experimental Pavement Markings on Urban Freeway Exit-Ramp Traffic Speeds

2000 ◽  
Vol 1705 (1) ◽  
pp. 116-121 ◽  
Author(s):  
Richard A. Retting ◽  
Hugh W. McGee ◽  
Charles M. Farmer
Keyword(s):  
New York ◽  
Motor Vehicle ◽  
Pavement Markings ◽  
Horizontal Curves ◽  
Passenger Vehicles ◽  
Lane Width ◽  
Before And After ◽  
Pavement Marking ◽  
Urban Freeway ◽  
Exit Ramp

Motor vehicle crashes on curved roadway sections occur more frequently and tend to be more severe than those on straight sections. Speed is a significant factor in many crashes that occur on curves. The effects on traffic speeds of special pavement markings intended to reduce speeds on freeway exit ramps with horizontal curves were examined. An experimental pavement marking pattern was employed that narrowed the lane width of both the curve and a portion of the tangent section leading into the curve by use of a gradual inward taper of existing edgeline or exit gore pavement markings or both. Traffic speeds were analyzed before and after installation of the pavement markings at four experimental ramps in New York and Virginia. Results indicated that the markings were generally effective in reducing speeds of passenger vehicles and large trucks. The markings were associated with significant reductions in the percentages of passenger vehicles and large trucks exceeding posted exit-ramp advisory speeds.

scholarly journals ANALISIS KINERJA RUAS JALAN RAYA SINGOSARI KABUPATEN MALANG

BANGUNAN ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 25
Author(s):  
Agustina P. F. Seran ◽  
Sugiyanto Sugiyanto ◽  
Pranoto Pranoto
Keyword(s):  
Network Performance ◽  
Service Level ◽  
Average Density ◽  
Level Of Service ◽  
Average Speed ◽  
The Road ◽  
Traffic Characteristics ◽  
Road Geometry ◽  
Road Performance ◽  
Side Friction

Abstrak:Peningkatan volume lalu lintas jika tidak diimbangi dengan kinerja jaringan jalan yang baik akan menyebabkan terjadinya kemacetan. Dengan mengetahui tingkat pelayanan jalan saat ini, dapat ditentukan penanganan yang tepat untuk meningkatkan kinerja jalan.Tujuan penelitian : (1) Mengetahui karakteristik lalu lintas Jalan Raya Singosari; (2) Mengetahui kinerja ruas Jalan Raya Singosari; (3) Mengetahui kinerja ruas Jalan Raya Singosari setelah diterapkan alternatif penanganan masalah lalu lintas yang terjadi.Metode dilakukan dengan survei geometri jalan, survei volume kendaraan, survei kecepatan kendaraan, dan survei hambatan samping. Analisis data menggunakan Manual Kapasitas Jalan Indonesia 1997. Penelitian dilakukan pada hari Minggu, Senin, dan Selasa pukul 06.00-22.00.Hasil penelitian : (1) Karakteristik lalu lintas pada ruas Jalan Raya Singosari arah Lawang, volume kendaraan tertinggi sebesar 2561,8 smp/jam pada pukul 16.30 – 17.30, kecepatan rata-rata 26,31 km/jam, dan kepadatan rata-rata 155,99 smp/km. Sedangkan untuk arah Malang, volume kendaraan tertinggi sebesar 2455,4 smp/jam pada pukul 16.00 -17.00, kecepatan rata-rata 29,34 km/jam, dan kepadatan rata-rata 132,35 smp/km. (2) Tingkat pelayanan rata-rata pada ruas Jalan Raya Singosari berada di rentang D dan E dengan tingkat pelayanan pada jam puncak adalah F. (3) Dengan alternatif pelebaran jalan dalam bentuk penambahan 1 lajur, tingkat pelayanan menjadi lebih baik di kelas C. Sedangkan dengan alternatif penerapan jalan tanpa hambatan samping, tingkat pelayanan menjadi lebih baik di kelas C dan D.Kata-kata kunci: kinerja jalan, tingkat pelayanan, jalan raya singosariAbstract: An increase in traffic volume if not balanced with good road network performance will cause congestion. By knowing the current level of road service, it can be determined the appropriate treatment to improve road performance. Research objectives: (1) Knowing the traffic characteristics of Singosari Highway; (2) Knowing the performance of the Singosari Highway section; (3) Knowing the performance of the Singosari Highway section after implementing alternative handling of traffic problems. The method is carried out by surveying the road geometry, surveying the volume of vehicles, surveying the speed of vehicles, and surveying side friction. Data analysis used the Indonesian Road Capacity Manual 1997. The study was conducted on Sundays, Monday and Tuesday from 06.00-22.00. The results of the study: (1) Traffic characteristics on Jalan Raya Singosari in the direction of Lawang, the highest vehicle volume was 2561.8 pcu hours at 16.30 - 17.30, average speed of 26.31 km / hour, and an average density of 155.99 pcu / km. Meanwhile, for Malang direction, the highest vehicle volume was 2455.4 pcu / hour at 16.00-17.00, the average speed was 29.34 km / hour, and the average density was 132.35 pcu / km. (2) The average service level on Jalan Raya Singosari is in the range D and E with the level of service at peak hours is F. (3) With the alternative of road widening in the form of adding 1 lane, the service level is better in class C. Whereas with the alternative of implementing roads without side obstacles, the level of service is better in classes C and D.Keywords: road performance, service level, Jalan Raya Singosari

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