Development and Performance of the Portable Skid Resistance Tester

1965 ◽  
Vol 38 (4) ◽  
pp. 840-862 ◽  
Author(s):  
C. G. Giles ◽  
B. E. Sabey ◽  
K. H. F. Cardew
Keyword(s):  
Field Trials ◽  
Test Surface ◽  
Skid Resistance ◽  
Textured Surfaces ◽  
Basic Principles ◽  
The Road ◽  
Factors Influencing ◽  
On The Road ◽  
And Performance ◽  
Patterned Tire

Abstract The portable skid-resistance tester can carry out a wide variety of measurements on the road and in the laboratory. This paper outlines the basic principles underlying the design of the tester and describes the laboratory and field trials conducted during the development of the instrument. The factors influencing its performance are emphasized. In its performance, the instrument behaves as a patterned tire skidding at 30 mph. It is particularly well suited for testing rough-textured surfaces, and readings are independent of gradient, camber, or crossfall on the test surface.

scholarly journals Degradation Prediction Model for Friction of Road Pavements with Natural Aggregates and Steel Slags

2019 ◽  
Vol 10 (1) ◽  
pp. 32 ◽  
Author(s):  
Bruno Crisman ◽  
Giulio Ossich ◽  
Paolo Bevilacqua ◽  
Roberto Roberti
Keyword(s):  
Residual Life ◽  
Steel Slag ◽  
Steel Production ◽  
Threshold Level ◽  
Skid Resistance ◽  
Concrete Pavements ◽  
Cumulative Number ◽  
The Road ◽  
On The Road ◽  
Natural Aggregates

Steel production wastes (steel slags) are used more often in asphalt concrete pavements as a valuable replacement for natural aggregates, which are becoming increasingly rare. In this paper authors investigate the polishing characteristics of aggregates, and in particular of steel slags, used in bituminous road surfacing, are a major factor in determining the resistance to skidding. The main purpose of the study is the identification of a suitable degradation model, based on friction indicators, in the laboratory, as well as the comparison of in-situ pavement skid resistance with the cumulative number of passing vehicles over the years. The model predicts the expected resistance to skidding of the road surface based on the knowledge of the polished stone value (PSV) of the aggregates and the expected traffic on the road. In this study, several types of aggregates were compared: steel slag, limestone, limestone and slag mixture, diabase, Criggion stone and basalt. Using a standard PSV test, it was found that the aggregates did not reach the lower value of skid resistance (equilibrium value). The analysis of the British Portable Number (BPN) data versus polishing time allowed to empirically derive a regression model for each investigated aggregate. Hence, it appears possible to define both an investigatory level and threshold level to predict the actual residual life of the pavement from the examination of skid resistance.

Mobile Learning Technologies

2011 ◽  
pp. 146-152 ◽  
Author(s):  
Diane M. Gayeski
Keyword(s):  
Health Care Professionals ◽  
High Speed ◽  
Learning Technologies ◽  
Social Environments ◽  
The Road ◽  
Powerful Learning ◽  
Large Numbers ◽  
On The Road ◽  
And Performance ◽  
Internet Connections

While educational and corporate training environments have made large investments in getting wired to high-speed Internet connections, our work and social environments are rapidly becoming more mobile and flexible. The Internet and organizationally based intranets are powerful learning and performance tools, as long as users have a high-speed connection and up-to-date computing equipment. Online learning and information is not nearly as convenient or reliable when learners need to access sites from their homes, hotel rooms, client locations, or while on the road. In corporate settings, large numbers of critical employees such as factory engineers, health care professionals, builders, and maintenance workers often do not even have offices in which to use a computer.

A First Investigation of Truck Drivers’ Preferences and Behaviors using a Prototype Cooperative Adaptive Cruise Control System

2018 ◽  
Vol 2672 (34) ◽  
pp. 39-48 ◽  
Author(s):  
Shiyan Yang ◽  
Steven E. Shladover ◽  
Xiao-Yun Lu ◽  
Hani Ramezani ◽  
Aravind Kailas ◽  
...  
Keyword(s):  
Adaptive Cruise Control ◽  
Aerodynamic Drag ◽  
Truck Drivers ◽  
Cruise Control ◽  
Fuel Savings ◽  
The Road ◽  
Cooperative Adaptive Cruise Control ◽  
And Behaviors ◽  
On The Road ◽  
And Performance

Cooperative adaptive cruise control (CACC) is a driver-assist technology that uses vehicle-to-vehicle wireless communication to realize faster braking responses in following vehicles and shorter headways compared with adaptive cruise control. This technology not only enhances road safety, but also offers fuel savings benefits as a result of reduced aerodynamic drag. The amount of fuel savings is dictated by the following distances and the driving speeds. So, the overarching goal of this work is to explore driving preferences and behaviors when following in “CACC mode,” an area that remains largely unexplored. While in CACC mode, the brake and throttle actions are automated. A human factors study was conducted to investigate truck drivers’ experiences and performance using CACC at shorter-than-normal vehicle following time gaps. “On-the-road” experiments were conducted by recruiting drivers from commercial fleets to operate the second and third trucks in a three-truck CACC string. The driving route spanned 160 miles on freeways in Northern California and five different time gaps between 0.6 and 1.8 seconds were tested. Factors such as cut-ins by other vehicles, road grades, and traffic conditions were found to influence the drivers’ opinions about use of CACC. The findings presented in this paper provide insights into the factors that will influence driver reactions to the deployment of CACC in their truck fleets.

scholarly journals THE BITUMEN BATCHING SYSTEM'S MODERNIZATION AND ITS EFFECTIVE ANALYSIS AT THE ASPHALT MIXING PLANT

Transport ◽  
2010 ◽  
Vol 25 (3) ◽  
pp. 325-335 ◽  
Author(s):  
Justas Bražiūnas ◽  
Henrikas Sivilevičius
Keyword(s):  
Asphalt Concrete ◽  
Additive Model ◽  
Technological Parameters ◽  
Destructive Effect ◽  
The Road ◽  
Weighted Matrix ◽  
Bitumen Content ◽  
Before And After ◽  
On The Road ◽  
And Performance

Some particular aspects such as the improvement methods of technological parameters for hot bitu‐ men storage in a pipeline transport system, transportation and dosed supply to batch asphalt mixing plant (AMP) are evaluated in this paper. Bitumen in asphalt concrete binds together the material of mineral particles into a strong conglomerate of a complicated structure, capable of withstanding the destructive effect of vehicles and the factors on the road pavements. The optimal amount of bitumen determined by calculation and laboratory testing should be maintained in mix batches of hot‐mix asphalt (HMA) obtained from AMP mixer. In the periodic type of the asphalt concrete blender mass of the weighted matrix in the all merging batcher's tanks should correspond in percents equally in the HMA to the designed amount of the job‐mix formula (JMF). The bitumen batcher does not always weigh bitumen portions precisely. Their mass deviations from the amount determined by JMF and its variation impair HMA composition and performance. In addition,, an additive model for calculating the effect of factors causing the variance of bitumen content in the produced HMA mixture is presented in this current paper as well. The data on statistical evaluation of bitumen batcher's modernization performed at certain Lithuanian Enterprise are discussed. The differences in structures of reconstructed and not reconstructed bitumen batching systems (BBS) are analysed and methods of determining modernization effectiveness are presented. The effectiveness of BBS is analysed too, defining the deviations of bitumen content in subsamples, taken and extracted everyday for two seasons (before and after the batcher's modernization) of HMA mixture production from the value of JMF and comparing them to the values of tolerances. The analysis of column charts and histograms shows that the made modernization helped to increase the precision of supplying the required amount of bitumen to HMA mixture insignificantly. However, the control of BBS has been considerably increased.

scholarly journals Use Effects on the Reflection of Macro Textured Surfaces

2016 ◽  
Vol 6 (1) ◽  
pp. 51-56
Author(s):  
P. A Ixtaina ◽  
A. Armas ◽  
B. Bannert ◽  
G.H. Marin
Keyword(s):  
Initial Conditions ◽  
Design Guidelines ◽  
Textured Surfaces ◽  
Temperature Spectrum ◽  
Street Lighting ◽  
The Road ◽  
Present Design ◽  
Lighting Systems ◽  
On The Road ◽  
The Impact

Abstract The emergence of led luminaries in street lighting has modified traditional design guidelines. The highest led energy efficiency allows keeping suitable lighting levels with less installed power. Thus, the present design line of a street lighting installation is closely related to the technological change: kind of led to be used, suitable lens, efficacy relationship regarding high pressure sodium, light colour temperature, spectrum. The “impact” associated to with led conversion relegates main aspects of street designs: effect of road reflective properties and installation depreciation. The wear produced by traffic, as well as the environmental conditions gradually modifies the road reflection matrix. In a street lighting installation, this change alters the luminance arrangement on the road together with the perception conditions. This phenomenon is a determining factor within the global concept of depreciation affecting lighting systems in general and also street lighting installations designed by the Luminance Technique. In the present work changes, due to use, in the shape of street reflection matrices of Argentinean highways are analyzed. The analyzed r-tables were obtained through “in-situ” measurements, with road reflectometer. A first group corresponds to the initial conditions of macro textured roads which were measured in the period 2001/2003. The second studied set contains r-tables of the same type, and according to its use the surfaces can be considered in steady state, assessed between 2005 and 2009. The study provides information about the shape of matrixes and its alteration, specularity and scale factor, relating such parameters with the possible effects on the resulting lighting.

scholarly journals Determinant Factors of Environmental Responsibility for the Passenger Car Users

2019 ◽  
Vol 9 (1) ◽  
pp. 219-224
Keyword(s):  
Demographic Variables ◽  
Environmental Responsibility ◽  
Passenger Car ◽  
Determinant Factors ◽  
The Road ◽  
Factors Influencing ◽  
The People ◽  
Manufacturer Association ◽  
Automobile Manufacturer ◽  
On The Road

The main aim of this study is to find out the demographic variables and their driving factors influencing the environmental responsibility of passenger car users. There are around 73.85 million passenger car was produced (OICA, 2018), and it is forecasted that 2 billion of car expected on the road before the end of 2040. Vehicles are the primary generator of emission per liter of fuel exhausts around 140-210 Co2 /km released in the air. The people who are using the vehicles are to be held responsible for the vulnerability which is resulted because of emission from the tailpipe. According to the Japan Automobile Manufacturer Association (JAMA), 80% of tailpipe emission was released by the vehicle users and the remaining 20% by the vehicle manufacturers. Therefore this paper understands the factors influencing the environmental responsibility of the passenger car users.

Research and Experiment on the Road Performance of Scoria (Volcanic Ash)

2011 ◽  
Vol 243-249 ◽  
pp. 4101-4105
Author(s):  
Zhen Hua Fan
Keyword(s):  
Theoretical Basis ◽  
Volcanic Ash ◽  
Detection Method ◽  
Road Construction ◽  
Construction Technology ◽  
Engineering Property ◽  
The Road ◽  
Road Performance ◽  
On The Road ◽  
And Performance

According to the tests and researches, this paper combine the constructing condition of scoria (volcanic ash) subgrade and lime-volcanic ash gradation macadam subgrade and the result of investigation and detection after the test section is completed, the physicochemical property, engineering property, compaction mechanism and performance, formation mechanism and increasing rule of strength of scoria (volcanic ash) and lime-volcanic ash are systematically analyzed, propose the construction technology and detection method of scoria (volcanic ash) subgrade and lime-volcanic ash gradation macadam subgrade, provide technical support and theoretical basis for application of scoria (volcanic ash) on road construction.

scholarly journals An Indoor Vehicle-in-the-Loop Simulation Platform Testing Method for Autonomous Emergency Braking

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Ying Gao ◽  
Xiangmo Zhao ◽  
Zhigang Xu ◽  
Jingjun Cheng ◽  
Wenwei Wang
Keyword(s):  
Traffic Safety ◽  
Autonomous Vehicle ◽  
Testing Time ◽  
Simulation Platform ◽  
The Road ◽  
Emergency Braking ◽  
Safety Function ◽  
Fast Solution ◽  
On The Road ◽  
And Performance

Autonomous vehicle (AV) is expected to be the ultimate solution for traffic safety, while autonomous emergency braking (AEB), as a crucial and fundamental active safety function of AV, has excellent potential for reducing fatalities and improving road safety. Although AV has the ability to cope with harsh conditions, it is supposed to be tested fully, systematically, and rigorously before it is officially commercialized. This study developed a novel indoor AV-in-the-loop (AVIL) simulation platform based on Client-Server (C/S) architecture for real full-scale AV testing. The proposed AVIL simulation platform consists of three parts: physical hardware components, software components, and various electrical interfaces that ensure the bidirectional virtual reality (VR) interaction. To validate the functionality and performance of the platform, this paper then adopted the Udwadia–Kalaba (U-K) approach to build the AEB system based on a typical driving situation due to the explicitness and simplicity of the U-K approach. Further, a group of real road-based experiments and AVIL-based experiments were conducted. The experimental results showed that the testing data obtained from the proposed AVIL platform have a high similarity to those of the real road tests, which means that the proposed AVIL platform is capable of simulating the AV running condition when it performs linear emergency braking on the road, thus confirming the feasibility and effectiveness of the AVIL platform for AV AEB testing. Simultaneously, the testing time and repeatability of the latter performed better. The findings of this study provide a new safe, effective, and fast solution to AV testing, and the practicability of this method has been verified.

scholarly journals Do wildlife warning reflectors elicit aversion in captive macropods?

2006 ◽  
Vol 33 (7) ◽  
pp. 583 ◽  
Author(s):  
Daniel Ramp ◽  
David B. Croft
Keyword(s):  
World Wide ◽  
Field Trials ◽  
Behavioural Response ◽  
Vehicle Collisions ◽  
Road Verge ◽  
Aversive Effect ◽  
The Road ◽  
Macropus Rufus ◽  
On The Road

A goal to reduce the frequency of animal–vehicle collisions is motivating extensive research on this topic world-wide. Over the last 30 years, one popular mechanism to warn wildlife of approaching vehicles has been the wildlife warning reflector, manufactured and distributed under the brands Swareflex (Austria) and Strieter-Lite (USA). These reflectors were designed to scare deer and other ungulates from roadways at night by reflecting light from the headlights of approaching vehicles into the eyes of animals on the road verge. Robust documentation of their effectiveness has been lacking, yet there has been a push in Australia to examine their efficacy with regard to medium to large macropodids. Field trials of the reflectors are problematic and difficult to design rigorously, so we chose to examine the behavioural response of two captive macropodid species (Macropus rufus and M. rufogriseus) to the reflectors on a simulated road in order to derive some indication as to their efficacy. The behavioural response to the reflectors was negligible for both species and not consistent with an aversive effect to deter road use or crossing. We conclude that they would be of little value in our efforts to reduce the frequency of collisions of kangaroos or wallabies with vehicles in Australia.

Friction of Rubber Wheels on Wet Asphalt Surfaces

2008 ◽  
Author(s):  
Noamen Bouzid ◽  
Bodo Heimann
Keyword(s):  
Water Film ◽  
Experimental Investigations ◽  
Test Surface ◽  
Automotive Safety ◽  
Friction Process ◽  
The Road ◽  
High Speeds ◽  
Vehicle Velocity ◽  
On The Road ◽  
Velocity Water

A reliable online prognosis of the grip between tire and road is a feature with a big potential for further improvements of the automotive safety. Existing grip potential prognosis systems for wet conditions are able only to describe the hydrodynamic decrease of friction at high speeds which depends on vehicle velocity, water film thickness and drainage properties both of the road surface and the tire. The present work deals with the friction at low speeds which depends on the road micro roughness. The experimental investigations are done in laboratory using a small solid rubber wheel and several asphalt samples. All parameters possibly influencing the friction process are varied. The influence of the test surface is found to be related to the micro texture and to be independent of any other parameters.

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