scholarly journals Track Behavior and Crash Risk Analysis of Passenger Cars on Hairpin Curves of Two-Lane Mountain Roads

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Zhigang Yu ◽  
Ying Chen ◽  
Xiaobo Zhang ◽  
Jin Xu
Keyword(s):  
Crash Risk ◽  
Passenger Cars ◽  
Left Turn ◽  
The Road ◽  
Dangerous Driving ◽  
Road Crash ◽  
Driving Conditions ◽  
The Right ◽  
Cutting Point ◽  
Right Turns

Hairpin curves are often employed in alignment layout and an important feature that identifies dangerous driving conditions for mountain roads. However, driving behaviors at hairpin curves remain ambiguous. Field driving tests were conducted in this study on one two-lane mountain road with 11 hairpin curves. Vehicle-mounted equipment was utilized to collect track and lateral distance between the wheels and the lane markings under naturally driving conditions. Track morphology and patterns, risks, and road crash mechanisms were analyzed. The main findings are as follows. Curve cutting was a typical method for negotiating hairpin curves, was observed for left and right turns, and can be classified into three types based on the location of the cutting point, namely, cutting at curve entry, cutting at curve middle, and cutting at curve exit. Based on the lateral positional relationships between tracks and lane markings, six track patterns are determined for left turns and four track patterns for right turns. When passing a right turn by cutting the curve, a driver occupied the right shoulder of the turn; therefore, there is a risk of colliding with the mountain or the guardrail. When making a left turn into hairpin curves, a driver occupied the right shoulder on curve exit, resulting in running off the road or colliding with the guardrail. More than 70% and 60% of drivers occupied the opposite lane when turning right and turning left, respectively, into a hairpin turn, which led to intertwining between the tracks in the two driving directions and therefore a risk of potential collisions.

Risk to Bicyclists in a Separated Path from Left Turns across Multiple Lanes: A Case for Protected-Only Left Turns

2021 ◽  
pp. 036119812110107
Author(s):  
Ray Saeidi Razavi ◽  
Peter G. Furth
Keyword(s):  
Opposite Direction ◽  
Signalized Intersections ◽  
Left Turn ◽  
The Road ◽  
Turn On ◽  
Road Users ◽  
Green Ball ◽  
Left Turns ◽  
The Right

At signalized intersections, permitted left turns (i.e., on a green ball, after yielding) across multiple through lanes and across a separated bike lane or bike path present a threat to bicyclist safety. A conflict study of two such intersections with a bidirectional bike path found that when cyclists cross while a vehicle is ready to turn left and there is no opposing through traffic to block it, the chance of the left-turning motorist yielding safely was only 9%, and the chance of their yielding at all—including yielding only after beginning the turn, then stopping in the opposing through lanes—was still only 37%. Motorist non-yielding rates were worse toward bikes arriving during green, toward bikes approaching from the opposite direction (i.e., riding on the right side of the road), and toward bikes facing a queue with multiple left turning vehicles. Of 112 cyclists who arrived on green when there was at least one left-turning car, but no opposing through traffic blocking it, 73 had to slow or stop to avoid a collision. Although these conflicts could be essentially eliminated using protected-only left turn phasing (turn on green arrow), common existing criteria prefer permitted left turns to reduce vehicular delay. A case study shows how, by considering multiple signalization alternatives, it can be possible to convert left turns to protected-only phasing without imposing a substantial delay burden on vehicles or other road users.

scholarly journals DRIVER’S REACTION TIME IN A SIMULATED, COMPLEX ROAD INCIDENT

Transport ◽  
2014 ◽  
Vol 32 (1) ◽  
pp. 44-54 ◽  
Author(s):  
Rafał Stanisław Jurecki ◽  
Tomasz Lech Stańczyk ◽  
Marek Jacek Jaśkiewicz
Keyword(s):  
Reaction Time ◽  
Traffic Safety ◽  
Regression Line ◽  
Reaction Times ◽  
Test Group ◽  
Steering Wheel ◽  
Accident Risk ◽  
Passenger Cars ◽  
The Road ◽  
The Right

This paper presents an overview of research on the behaviour of drivers in simulated accident situations. The research was carried out by the authors of this work as a part of a research N N509 549 040 funded by the National Science Centre including new accident situations. The paper presents a description of the methodology and implementation of research on a track. During the tests, the simulation concerns about an accident risk situation involving pedestrians and passenger cars intruding the road area. In contrast to earlier research carried out by the authors, the scenario included the possibility of a pedestrian ‘entering’ from behind a curtain, both from the left and from the right sides of the road. This was possible thanks to a specially developed test stand. The paper analyses the values of driver’s reaction times characteristic to driver’s impact on: acceleration control pedals, service brake and steering wheel. In addition to the determination of average reaction time values and the regression line for the test group of 30 drivers, the assessment of the frequency of drivers taking individual defensive reactions was carried out. Keywords: traffic safety; collision; road accidents; regression equation; simulation.

scholarly journals Influence of Selected Vehicle Maneuvers on Reduction of the Urban Roads Capacity

2019 ◽  
Vol 21 (4) ◽  
pp. 81-89
Author(s):  
Jan Celko ◽  
Matus Kovac ◽  
Kristina Huszarova
Keyword(s):  
Left Turn ◽  
Urban Road ◽  
The Road ◽  
Critical Gap ◽  
Turn On ◽  
Road Section ◽  
Road Intersections ◽  
On The Road ◽  
The Right ◽  
Curve Radius

Capacity assessment of urban roads according to Slovak standard does not sufficiently take into account the influence of vehicle maneuvers on road section performance between the two intersections. This research analyzed turning relations on selected urban road intersections and the influence of right turn and left turn on major stream speed changes. For the purpose of determining the influence of the right turn on decrease in capacity, measurements were carried out at 7 uncontrolled intersections with curve radius ranging from 6 to 30m. To determine the influence of the left turn on the capacity of urban road a critical gap was evaluated, using the Raff’s, method, based on the analysis of accepted and rejected gaps in the major traffic stream, which was one of the main inputs for simulations. The findings were used to determine the influence of selected maneuvers on the road capacity, which led to a proposal for reduction coefficients based on computational analysis performed using simulations in PTV VISSIM.

scholarly journals Traffic Management of the Congested Urban-suburban Arterial Roads

2019 ◽  
Author(s):  
András Szele ◽  
Lajos Kisgyörgy
Keyword(s):  
Traffic Management ◽  
Road Network ◽  
Infrastructure Development ◽  
Passenger Cars ◽  
The Road ◽  
Network Operation ◽  
On The Road ◽  
The Right ◽  
Traffic Operation ◽  
The City

Managing the congestion is an old and legitimate claim of the cities. However, in spite of the promising solutions, the use of passenger cars outside the city centers did not decrease. The still hot topic requires a real solution.The goal of the traffic planning and management was to serve the traffic demands but with the increase in traffic, infrastructure development could not keep up, so this goal - theoretically - is not valid anymore. We are in the midst of a paradigm shift: the old goals are obviously not working, but new goals and the tools needed to achieve them have not yet been developed.According to the presented research, the operation of urban-suburban rush hour congestion radically differs from the way we have assumed so far, so a new framework was developed that describes this traffic operation. This framework allows us to look for new and valid management solutions and set new strategic and operational goals. In this paper, it is proposed not to build infrastructure for traffic demands, but to adapt the traffic demands to the infrastructure, by creating the optimal saturated traffic flow. This will prevent negative traffic dynamics and impacts on the network and provide higher quality and a more reliable road network operation. The research results have led us to theoretical questions such as the right of the limitation of the free routing on the road network.

Observations on the Provenance of the Thames Valley Pick, Swalecliffe, Kent

1926 ◽  
Vol 5 (2) ◽  
pp. 224-230 ◽  
Author(s):  
F. H. Worsfold
Keyword(s):  
Subject Matter ◽  
Sloping Ground ◽  
Relative Age ◽  
Treasure Trove ◽  
The Road ◽  
University College London ◽  
Exact Position ◽  
The Subject ◽  
London Clay ◽  
The Right

From the Marine Parade, Tankerton, Whitstable, looking East, one obtains a capital view of Tankerton Bay, Swalecliffe, in which my discoveries have been made which are to form the subject matter of this paper. The grassy cliff at Priest and Sow corner at the end of the road stands at 55 O.D. This height gradually declining round the arc of the bay, to die out entirely in the Long Rock occupying the middle distance and through which the Swalecliffe Brook discharges into the sea. Just beyond, a little to the right, are the disused Swalecliffe Brick Works, with Stud Hill and Hampton lying further back. To the left and edging the horizon, Herne Bay Pier is clearly discernable. The accompanying copy of (Plate I.) the 25-in. Ordnance map of this Tankerton Bay section gives the exact position of the 650 yards from the Parish Boundary Stone eastwards indicated thereon with a X in which are found the gravels and brick-earths which have proved so rich in archaeological treasure trove. The whole of this south-easterly directioned well-drained gently sloping ground, from the Priest and Sow corner to the Swalecliffe brook, forms an ideal camping site. Last April a paper was read by me before the Geological Association, at University College, London, entitled “An Examination of the Contents of the Brick Earths and Gravels of Tankerton Bay, Swalecliffe, Kent,” in which the geological aspect of this section was fairly exhaustively treated, so that in this particular it will be unnecessary for me to do more than give a brief summary of the results of that examination as to the relative age and stratigraphical sequence of the Drift material found here overlying the London Clay.

Determination of Resistance to Abrasive Wear. VIII. Influence of Softeners in Tests with the Akron-Croydon and Du Pont Machines

1949 ◽  
Vol 22 (1) ◽  
pp. 259-262
Author(s):  
J. F. Morley
Keyword(s):  
Unit Area ◽  
Published Data ◽  
The Road ◽  
Abrasive Surface ◽  
Abrasive Power ◽  
The Difference ◽  
On The Road ◽  
The Right ◽  
Abrasion Testing

Abstract These experiments indicate that softeners can influence abrasion resistance, as measured by laboratory machines, in some manner other than by altering the stress-strain properties of the rubber. One possible explanation is that the softener acts as a lubricant to the abrasive surface. Since this surface, in laboratory abrasion-testing machines, is relatively small, and comes repeatedly into contact with the rubber under test, it seems possible that it may become coated with a thin layer of softener that reduces its abrasive power. It would be interesting in this connection to try an abrasive machine in which a long continuous strip of abrasive material was used, no part of it being used more than once, so as to eliminate or minimize this lubricating effect. The fact that the effect of the softener is more pronounced on the du Pont than on the Akron-Croydon machine lends support to the lubrication hypothesis, because on the former machine the rate of wear per unit area of abrasive is much greater. Thus in the present tests the volume of rubber abraded per hr. per sq. cm. of abrasive surface ranges from 0.03 to 0.11 cc. on the du Pont machine and from 0.0035 to 0.0045 cc. on the Akron-Croydon machine. On the other hand, if the softener acts as a lubricant, it would be expected to reduce considerably the friction between the abrasive and the rubber and hence the energy used in dragging the rubber over the abrasive surface. The energy figures given in the right-hand columns of Tables 1 and 3, however, show that there is relatively little variation between the different rubbers. As a test of the lubrication hypothesis, it would be of interest to vary the conditions of test so that approximately the same amount of rubber per unit area of abrasive is abraded in a given time on both machines; this should show whether the phenomena observed under the present test conditions are due solely to the difference in rate of wear or to an inherent difference in the type of wear on the two machines. This could most conveniently be done by considerably reducing the load on the du Pont machine. In the original work on this machine the load was standardized at 8 pounds, but no figures are quoted to show how abrasion loss varies with the load. As an addition to the present investigation, it is proposed to examine the effect of this variation with special reference to rubbers containing various amounts and types of softener. Published data on the influence of softeners on the road wear of tire rubbers do not indicate anything like such large effects as are shown by the du Pont machine. This throws some doubt on the value of this machine for testing tire tread rubbers, a conclusion which is confirmed by information obtained from other workers.

An Introduction to Global Health Delivery

2021 ◽  
Author(s):  
Joia Mukherjee ◽  
Paul Farmer
Keyword(s):  
Health Care ◽  
Global Health ◽  
Access To Health Care ◽  
Right To Health ◽  
Treatment Access ◽  
The Road ◽  
Health Delivery ◽  
Positive Side ◽  
Access To Health ◽  
The Right

What has called so many young people to the field of global health is the passion to be a force for change, to work on the positive side of globalization, and to be part of a movement for human rights. This passion stems from the knowledge that the world is not OK. Impoverished people are suffering and dying from treatable diseases, while the wealthy live well into their 80s and 90s. These disparities exist between and within countries. COVID-19 has further demonstrated the need for global equity and our mutual interdependence. Yet the road to health equity is long. People living in countries and communities marred by slavery, colonialism, resource extraction, and neoliberal market policies have markedly less access to health care than the wealthy. Developing equitable health systems requires understanding the history and political economy of communities and countries and working to adequately resource health delivery. Equitable health care also requires strong advocacy for the right to health. In fact, the current era in global health was sparked by advocacy—the activist movement for AIDS treatment access, for the universality of the right to health and to a share of scientific advancement. The same advocacy is needed now as vaccines and treatments are developed for COVID-19. This book centers global health in principles of equity and social justice and positions global health as a field to fulfill the universal right to health.

scholarly journals Characterisation of cyclists’ willingness to pay for green initiatives at Africa’s largest cycle tour

2016 ◽  
Vol 19 (3) ◽  
pp. 432-439
Author(s):  
Melville Saayman ◽  
Waldo Krugell ◽  
Andrea Saayman
Keyword(s):  
Willingness To Pay ◽  
Carbon Footprint ◽  
Climate Change Mitigation ◽  
Demographic Variables ◽  
The Road ◽  
Road Cycling ◽  
Different Types ◽  
On The Road ◽  
The Right ◽  
Change Mitigation

The Cape Argus Pick n Pay Cycle Tour is a major event on the road cycling calendar. The majority of cyclists travel significant distances and participation produces a substantial carbon footprint. This paper examines participants’ willingness to pay to offset their carbon footprint. The purpose of this paper is to make a contribution to the literature by linking willingness to pay to attitudes towards or beliefs (green views) about the initiatives in place, to ensure a greener cycle tour. Factor analysis is used to identify different types of cyclists, based on their green views: those with green money, those who prefer green products and the “re-cyclers”. The results of the regression analysis reveal that socio-demographic variables and the right attitude towards the environment are significant predictors of stated willingness to pay for climate change mitigation.

scholarly journals Lane Change Behavior on Freeways: An Online Survey Using Video Clips

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
V. L. Knoop ◽  
M. Keyvan-Ekbatani ◽  
M. de Baat ◽  
H. Taale ◽  
S. P. Hoogendoorn
Keyword(s):  
Online Survey ◽  
Simulation Models ◽  
Lane Changes ◽  
The Road ◽  
Video Clips ◽  
Road Capacity ◽  
Change Behavior ◽  
Instrumented Vehicle ◽  
The Moment ◽  
The Right

Freeways form an important part of the road network. Yet, driving behavior on freeways, in particular lane changes and the relation with the choice of speed, is not well understood. To overcome this, an online survey has been carried out. Drivers were shown video clips, and after each clip they had to indicate what they would do after the moment the video stopped. A total of 1258 Dutch respondents completed the survey. The results show that most people have a strategy to choose a speed first and stick to that, which is the first strategy. A second, less often chosen, strategy is to choose a desired lane and adapt the speed based on the chosen lane. A third strategy, slightly less frequently chosen, is that drivers have a desired speed, but contrary to the first strategy, they increase this speed when they are in a different lane overtaking another driver. A small fraction have neither a desired speed nor a desired lane. Of the respondents 80% use the right lane if possible, and 80% avoid overtaking at the right. Also 80% give way to merging traffic. The survey was validated by 25 survey respondents also driving an instrumented vehicle. The strategies in this drive were similar to those in the survey. The findings of this work can be implemented in traffic simulation models, e.g., to determine road capacity and constraints in geometric design.

Improvement of the visual warning system for various driving and road conditions in road transportation

2017 ◽  
Vol 232 (2) ◽  
pp. 175-187 ◽  
Author(s):  
Güray Tonguç ◽  
İsmail Hakkı Akçay ◽  
Habib Gürbüz
Keyword(s):  
Warning System ◽  
Weather Conditions ◽  
The Other ◽  
Accelerometer Data ◽  
Road Transportation ◽  
Accelerometer Sensor ◽  
The Road ◽  
Information Displays ◽  
Driving Conditions ◽  
Vehicle Information

This study aims to identify the potential adverse driving conditions which result from driver behavior, road surfaces and weather conditions for vehicles during a cruise, and to inform the drivers of the other vehicles moving on the same route. Adverse driving condition scenarios were developed via acceleration data in lateral, longitudinal and vertical directions gathered by using an accelerometer sensor placed at the gravity center of the test vehicles. The drivers were warned through the symbols designed according to the developed scenarios in different shapes and colors, displayed on an information screen showing the position of the vehicle. Three different software programs were used for gathering and evaluating the accelerometer data, storing scenario-specific symbols on the internet and transferring these symbols to the other vehicle information displays. The road tests were performed in conditions present in Turkey. It was observed that the vehicle drivers were alerted with the warning symbols which were designed for dangerous road and driving conditions with a latency of approximately 6s on Google maps which appeared on the driver information screen.

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