scholarly journals A New Model of Stopping Sight Distance of Curve Braking Based on Vehicle Dynamics

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Rong-xia Xia ◽  
De-hua Wu ◽  
Jie He ◽  
Ya Liu ◽  
Deng-feng Shi
Keyword(s):  
Calculation Model ◽  
Emergency Situations ◽  
Process Dynamics ◽  
Sight Distance ◽  
Straight Line ◽  
Braking Distance ◽  
Vehicle Test ◽  
Stopping Sight Distance ◽  
Braking Process ◽  
Experimental Values

Compared with straight-line braking, cornering brake has longer braking distance and poorer stability. Therefore, drivers are more prone to making mistakes. The braking process and the dynamics of vehicles in emergency situations on curves were analyzed. A biaxial four-wheel vehicle was simplified to a single model. Considering the braking process, dynamics, force distribution, and stability, a stopping sight distance of the curve braking calculation model was built. Then a driver-vehicle-road simulation platform was built using multibody dynamic software. The vehicle test of brake-in-turn was realized in this platform. The comparison of experimental and calculated values verified the reliability of the computational model. Eventually, the experimental values and calculated values were compared with the stopping sight distance recommended by the Highway Route Design Specification (JTGD20-2006); the current specification of stopping sight distance does not apply to cornering brake sight distance requirements. In this paper, the general values and limits of the curve stopping sight distance are presented.

Truck braking distance and speed estimates

1986 ◽  
Vol 13 (4) ◽  
pp. 412-422 ◽  
Author(s):  
Francis P. D. Navin
Keyword(s):  
Traffic Accident ◽  
Centre Of Mass ◽  
Average Ability ◽  
Sight Distance ◽  
Truck Accidents ◽  
Police Agencies ◽  
Braking Distance ◽  
Stopping Sight Distance ◽  
Basic Equations ◽  
Final Equation

The most frequently cited cause of truck accidents is “speed too fast for prevailing conditions.” To cite this cause, a speed estimate is necessary. This paper shows the factors that should be considered. The factors most useful in estimating a truck's braking capability include vehicle configuration, loading, location of the centre of mass, and axles with brakes. The exact value of some of the variables is difficult to obtain.The formulation proposed in this paper builds on a simple and effective procedure used by police agencies to estimate speed from skid marks. The formula given by R. Rivers' “Traffic accident investigator's handbook” is formalized and the elements in his correction factor N are derived. Basic equations for the braking of straight trucks and combinations are derived. The difficulty of implementing the equations in practice for all but the simplest situation is obvious from the complexity of the equations. A lumping of all the parameters into a simplified form is developed based on truck stopping distances obtained from published experimental data. All the trucks in the data had well-adjusted brakes. The final equation to estimate speed from a truck's skid marks accounts for the average ability of such vehicles to stop as well as the variance in stopping ability. Key words: truck braking, braking efficiency, stopping sight distance, skid marks.

Driver Braking Performance in Stopping Sight Distance Situations

2000 ◽  
Vol 1701 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Daniel B. Fambro ◽  
Rodger J. Koppa ◽  
Dale L. Picha ◽  
Kay Fitzpatrick
Keyword(s):  
Emergency Situation ◽  
Practical Significance ◽  
Braking Performance ◽  
Additional Information ◽  
Emergency Situations ◽  
Sight Distance ◽  
Directional Control ◽  
Average Maximum ◽  
Stopping Sight Distance ◽  
Maximum Deceleration

Assumed driver braking performance in emergency situations is not consistent in the published literature. A 1955 study stated that in an emergency situation “it is suspected that drivers apply their brakes as hard as possible.” This idea differs from a 1984 report that states drivers will “modulate”their braking to maintain directional control. Thus, additional information is needed about driver braking performance when an unexpected object is in the roadway. In this research driver braking distances and decelerations to both unexpected and anticipated stops were measured. The study design allowed for differences in vehicle handling and driver capabilities associated with antilock braking systems (ABS), wet and dry pavement conditions, and the effects of roadway geometry. Vehicle speeds, braking distances, and deceleration profiles were determined for each braking maneuver. The research results show that ABS result in shorter braking distances by as much as 30 m at 90 km/h. These differences were most noticeable on wet pavements where ABS resulted in better control and shorter braking distances. Braking distances on horizontal curves were slightly longer than on tangent sections; however, they were not large enough to be of practical significance. Maximum deceleration during braking is independent of initial velocity, at least in the range of speeds tested. Differences were noted in individual driver performance in terms of maximum deceleration. Although maximum deceleration was equal to the pavement’s coefficient of friction for some drivers, the average maximum deceleration was about 75 percent of that level. Overall, drivers generated maximum decelerations from 6.9 to 9.1 m/s2. The equivalent constant deceleration also varied among drivers. Based on the 90-km/h data, 90 percent of all drivers without ABS chose equivalent constant decelerations of at least 3.4 m/s2 under wet conditions, and 90 percent of all drivers with ABS chose equivalent constant deceleration of at least 4.7 m/s2 on dry pavements.

scholarly journals ANALISIS PERILAKU PENGENDARA DAN JARAK PANDANG HENTI SEPEDA MOTOR MATIC

2018 ◽  
Vol 1 (2) ◽  
pp. 55
Author(s):  
Erika Buchari ◽  
Ahmad Gilang Dwi Junanta
Keyword(s):  
Linear Regression ◽  
Linear Regression Model ◽  
Sight Distance ◽  
Moving Vehicles ◽  
Braking Distance ◽  
Motorcycle Industry ◽  
Multi Linear Regression ◽  
Stopping Sight Distance ◽  
The Relationship ◽  
The Ideal

The growth of Matic-Motorcycle in Indonesia is increased steeply lately. According to Assosiasion of Indonesian Motorcycle Industry, AISI the sales of matic motorcycle have achieved 75,49% (3,639,000) of the wholesaler 4,821,000. In fact, motorcycle users do not realize that automatic motorcycle’s characteristics especially braking distance are different with those of non-automatic motorcycles. The different way of riding can cause uncontrolled vehicles during braking, when promptly change speed either faster or slower. Stopping sight distance is the distance needed by riders in order to stop their moving vehicles after seeing the obstacles in the front. This research is seeking to know the behavior of motorcycle users and stopping sight distance that is ideal for the users of automatic motorcycles. Multi linear Regression model is made to find out the relationship between stopping sight distance and other variables such as speed, machine capacity, type of brakes etc. From this model, it can be derived the ideal stopping sight distance which is affected by speed, machine capacity, type of front brakes. Perkembangan sepeda motor matic di Indonesia mengalami pertumbuhan yang sangat pesat beberapa tahun belakangan ini. Menurut data dari asosiasi industri sepeda motor Indonesia( AISI,2015) penjualan sepeda motor matic mengalami pertumbuhan yang sangat pesat dibandingkan dan motor bebek dan sport, yaitu 75,49% (3,639 juta matic dari penjualan 4,821 juta motor keseluruhan). Fakta di lapangan, pengguna tidak menyadari beda karakteristik kendaraan motor matic dengan non matic. Perbedaan ini mengakibatkan tidak terkontrolnya kecepatan kendaraan dimana seringnya terjadi perubahan percepatan dan perlambatan pada kendaraan tersebut. Jarak pandangan henti adalah jarak yang dibutuhkan oleh pengendara untuk menghentikan kendaraannya yang bergerak setelah melihat adanya rintangan pada lajur jalannya. Penelitian ini ingin mengetahui perilaku pengendara dan jarak pandang henti yang ideal bagi pengendara sepeda motor matic. Model Multi linear Regression hubungan Jarak pandangan henti dengan variable kecepatan, kapasitas mesin dan jenis rem diteliti. Hasilnya diperoleh jarak henti ideal yang dipengaruhi oleh kecepatan, kapasitas mesin, dan jenis rem depan.

Research of Safe Speed at Snow on Freeway Based on Braking Model of Stopping Sight Distance

2012 ◽  
Vol 209-211 ◽  
pp. 837-840
Author(s):  
Jian Jun Wang ◽  
Fa Yao Xu ◽  
A Jin Ma
Keyword(s):  
Friction Coefficient ◽  
Surface Friction ◽  
Calculation Model ◽  
Driving Safety ◽  
Adhesion Coefficient ◽  
Distance Analysis ◽  
Sight Distance ◽  
Snow Condition ◽  
Model Derivation ◽  
Stopping Sight Distance

The brake model derivation based on the kinematics of the stopping sight distance analysis, considering the freeway visibility and road surface friction coefficient, put forward freeway safety speed calculation model in snow condition, reach maximum safe speed of snow freeway in a different visibility and road adhesion coefficient snow condition, provide a management reference for freeway snow driving safety.

scholarly journals Influence of Night Rainfall on Stopping Sight Distance on Dark Roadways

2020 ◽  
Vol 14 (1) ◽  
pp. 32-37
Author(s):  
Ben-Edigbe J.E ◽  
Makinde O. O
Keyword(s):  
Rain Gauge ◽  
Weather Data ◽  
Vehicle Type ◽  
Sight Distance ◽  
Braking Distance ◽  
Research Gap ◽  
Stopping Sight Distance ◽  
Travel Delay ◽  
Distance Travel ◽  
Rainfall Impact

Aim: To investigate the influence of night rainfall on stopping sight distance on dark roadways. Background: This study fills the research gap in stopping sight distance by looking at night rainfall impact on stopping sight distance on dark roadways. Objectives: To determine stopping sight distance under night rainfall (light, moderate and heavy) on dark roadways and compare the results with stopping sight distance under dry night on dark roadways. Methods: In a ‘with and without’ night rainfall impact studies, traffic volume, speed, vehicle type and rainfall data were collected at selected sites. All surveyed sites had rain gauge within the catchment area of about 1km. Rainfall intensity was divided into three groups (light, moderate, and heavy). Dry weather data were used as a control parameter. Results: Results show that the average SSD decrease attributed to light rainfall is 15.2m (14%), moderate rainfall 18.3m (16.8%), and heavy rainfall 21.2m (19.2%). Conclusion: Based on the results and findings, it is correct to conclude that the effect of night rainfall on dark roadways stopping sight distance is somewhat aberrant. It is also correct to suggest that night rainfall on dark roadways will cause a decrease in perception distance travel delay, an increase in braking distance and stopping sight distance.

scholarly journals Safe Braking Distance at Signalized Intersection

2019 ◽  
Vol 9 (1) ◽  
pp. 2774-2781
Keyword(s):  
Goodness Of Fit ◽  
Speed Limit ◽  
Left Turn ◽  
Dilemma Zone ◽  
Goodness Of Fit Tests ◽  
Sight Distance ◽  
Braking Distance ◽  
Stopping Sight Distance ◽  
Pass Through ◽  
Signalised Intersection

Signalised intersection is an area where most of the drivers having dilemma in making decision to either pass through the intersection or stop when the light turns to yellow. During this phase, a sudden deceleration and incorrect estimate of intersection clearance time cause rear-end collision, severe right-angle crash and left-turn head-on collision. Therefore, the aim of this study was to determine the safe braking distance at signalised intersection by using the concept of stopping sight distance, so that a set of road marking and road sign can be proposed to help the driver in making decision within the dilemma zone. Samples of vehicle’s approaching speed were collected at a signalised intersection within the Ipoh-Lumut Highway in Perak Tengah. Statistical analysis showed that the observed 15th and 85th percentile speed at the intersection were 66.2km/h and 88.5km/h, with a mean and standard deviation of 77.5km/h and 9.99km/h. Goodness-of-fit tests showed that the distribution of the approaching speed at the intersection was normally distributed with a probability of 14.4%. It was concluded that safe braking distance from the stopping line of the signalised intersection is between 97m for lower speed limit to 152m for the upper speed limit.

Controlling Crest Vertical Curvature Rates Based on Variable Grade Stopping Sight Distance Calculation

2015 ◽  
Vol 2521 (1) ◽  
pp. 31-44
Author(s):  
Stergios Mavromatis ◽  
Nikiforos Stamatiadis ◽  
Basil Psarianos ◽  
George Yannis
Keyword(s):  
Design Parameters ◽  
Control Element ◽  
Mass Model ◽  
Road Design ◽  
Sight Distance ◽  
Wide Range ◽  
Significant Difference ◽  
Road Geometry ◽  
Stopping Sight Distance ◽  
Braking Process

Stopping sight distance (SSD) is a key control element that directly affects the suggested values of crucial road design parameters. Although there is a significant difference in SSD values between upgrades and downgrades, many design policies ignore the grade effect during vehicle braking on variable grades. Such a case occurs during the determination of crest vertical curvature rates in which the relevant SSD values are extracted assuming leveled road geometry. This paper investigates a possible deficiency of such an approach with regard to cases in which the length of the vertical curve exceeds the control SSD values. SSD calculation on variable grades during the braking process was addressed through a recently developed process that related the point mass model and the laws of mechanics. For a wide range of design speed values, charts illustrating the required SSDs were drawn as a function of negative ending grade values related to the control crest vertical curve rates adopted by AASHTO. The process revealed numerous SSD shortage areas for which revised crest vertical curvature rates were provided to grant SSD adequacy throughout the vehicles' braking process. This paper also aimed to provide designers with ready-to-use vertical design tools associated with amended vertical curvature rates to AASHTO's road functional classification as a function of the crest vertical curve's exit grade value.

The Analysis of the Key Problems about Traffic Accident Speed Identification Based on Braking Traces

2013 ◽  
Vol 756-759 ◽  
pp. 4752-4757
Author(s):  
Zhi Wei Guan ◽  
Shao Hua Wang ◽  
Wei Qiang Liang ◽  
Ming Feng Zheng ◽  
Lin Wu ◽  
...  
Keyword(s):  
Traffic Accident ◽  
Performance Test ◽  
National Standard ◽  
Test Report ◽  
Actual Case ◽  
Braking Performance ◽  
Braking Distance ◽  
Braking Process ◽  
Judicial Expertise ◽  
Speed Identification

In order to improve the impartiality and objectivity of judicial expertise, the key problems about traffic accident speed identification are analyzed and the speed of vehicle is calculated by using the braking performance test report with reference to the national standard and automobile theory. The automobile dynamics of driver braking process is analyzed, all kinds of key problems such as the braking distance, braking coordination time, braking speed, longitudinal sliding coefficient of adhesion are combined with the braking performance test report, and the method of determining the longitudinal sliding coefficient of adhesion is proposed, the instantaneous velocity before the collision is calculated. Finally, the method is used to calculate the speed of an actual case, and simulated in the software of PC-Crash, the results are consistent, verifying that the speed identification method is correct.

Sight distance red zones on combined horizontal and sag vertical curves

1998 ◽  
Vol 25 (4) ◽  
pp. 621-630 ◽  
Author(s):  
Yasser Hassan ◽  
Said M Easa
Keyword(s):  
Quantitative Analysis ◽  
Three Dimensional ◽  
The Other ◽  
Two Dimensional ◽  
Horizontal Curve ◽  
Sight Distance ◽  
Stopping Sight Distance ◽  
Three Dimensional Models ◽  
Highway Alignment ◽  
Current Standards

Coordination of highway horizontal and vertical alignments is based on subjective guidelines in current standards. This paper presents a quantitative analysis of coordinating horizontal and sag vertical curves that are designed using two-dimensional standards. The locations where a horizontal curve should not be positioned relative to a sag vertical curve (called red zones) are identified. In the red zone, the available sight distance (computed using three-dimensional models) is less than the required sight distance. Two types of red zones, based on stopping sight distance (SSD) and preview sight distance (PVSD), are examined. The SSD red zone corresponds to the locations where an overlap between a horizontal curve and a sag vertical curve should be avoided because the three-dimensional sight distance will be less than the required SSD. The PVSD red zone corresponds to the locations where a horizontal curve should not start because drivers will not be able to perceive it and safely react to it. The SSD red zones exist for practical highway alignment parameters, and therefore designers should check the alignments for potential SSD red zones. The range of SSD red zones was found to depend on the different alignment parameters, especially the superelevation rate. On the other hand, the results showed that the PVSD red zones exist only for large values of the required PVSD, and therefore this type of red zones is not critical. This paper should be of particular interest to the highway designers and professionals concerned with highway safety.Key words: sight distance, red zone, combined alignment.

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