Width Of Shoulder Research Articles

Road safety improving in blackspot of Mount Bromo tourist road access, East Java

Mount Bromo in East Java is one of Indonesia’s priority tourist attractions. Safe, secure, orderly, and smooth traffic access is needed to support tourism. Safe roads can be an essential part of realizing this. This study aims to prioritize handling blackspots to discover safe roads. The research was conducted on three access roads to Mount Bromo from Probolinggo: Jalan Raya Sukapura, Jalan Raya Bromo, and Jalan Raya Lumbang. Analysis of the probability value of accidents, the impact value of the severity of accident victims, and the risk value of accidents are used to determine handling priorities. The results of the analysis obtained priority handling for Blackspot 1 by increasing the width of the road shoulder, Blackspot 2 by providing a crossing integrated with APILL, Blackspot 3 by completing street lighting and increasing lane width, Blackspot 4 by completing street lighting, and Blackspot 5 by increasing lane width. Prioritizing the handling of accident-prone locations in the road and environmental aspects can be done by reviewing the risk value of accidents for each road sub-component. A safe road will be realized at the Blackspot location.

Research on left hard shoulder width of super multilane highway based on PTSU operation.

Part-time shoulder use (PTSU) is a traffic strategy that temporarily uses the shoulder as a lane when necessary. Research has shown that, when a hard shoulder is required to set the traffic function, the left hard shoulder is preferable. Super multilane highways are usually equipped with left hard shoulders of sufficient width, but the wide cross-sectional characteristics make it difficult for vehicles to turn into the emergency parking lane to avoid a breakdown or accident in the lane, which is an ideal implementation object of PTSU. In this study, two virtual simulation scenarios for PTSU were created: one with the left hard shoulder open and used as a travel lane, and the other with the left hard shoulder closed and its original function restored. Vehicle driving data were collected through driving simulation experiments to reveal the influence of the left hard shoulder on vehicle handling stability. The optimal width of the left hard shoulder was determined by ANOVA and comparison of the mean and standard deviation. The purpose of this study was to quantify the effect of the width of the left hard shoulder on the driving stability of vehicles in the inside lane under PTSU and determine the ideal shoulder width by comparing the stability parameters of vehicles.

Research on the Safety of the Left Hard Shoulder in a Multi-Lane Highway Based on Safety Performance Function

The left hard shoulder plays an important role in the event of an emergency on the inside of a multi-lane highway, but past studies have not been able to clarify the criteria for its installation or quantify the safety impact of its installation on the left side. In order to study the influence of the left hard shoulder on the safety of vehicles traveling on multi-lane highways, based on past studies that only studied the situation of four-lane highways, this paper firstly constructs a multi-lane highway simulation model under different numbers of lanes based on the VISSIM traffic simulation and uses Surrogate Safety Assessment Model (SSAM) to study the conflict characteristics of multi-lane highway vehicles under different numbers of lanes. Based on the above findings, this paper introduces the Safety Performance Function (SPF) to construct a multi-lane freeway accident prediction model, calibrates the model by adding the indexes affected by the left side hard shoulder to the basic prediction mode, and uses the historical accident data of the Badou-Shihu section of the Guangdong Northern Second Ring Highway as the basis to study the differences in accident rates of the investigated section before and after setting the left hard shoulder. The study showed that the average Time to Collision (TTC) increased by 57.2%, Maximum Deceleration (MaxD) increased by 19.2%, and Delta Speed (DeltaS) increased by 15.3% after setting hard shoulders on the left side of multi-lane freeways, and traffic conflicts on multi-lane freeways were significantly reduced, and safety was improved considerably. In addition, the rear-end conflict rate decreased by 0.17%, 0.75%, and 4.6% after setting hard shoulders on the left side of one-way three, four, and five lanes, respectively, indicating that hard shoulders on the left side are the most effective in improving the safety of one-way five-lane freeways. The accident prediction results show that within the reasonable setting range of the left hard shoulder width (0~4 m), the accident rate decreases by about 1.5% for every 0.5 m increase if only the influence of the left hard shoulder width is considered. Without considering other factors, increasing the width of the hard shoulder on the left side can reduce the number of accidents. This indicates a significant safety improvement for a one-way five-lane highway after setting the hard shoulder on the left side, and the conclusion is consistent with the simulation results. In this paper, based on past research, the research object is extended to one-way three-, four-, and five-lane highways. The findings of this paper can help the road authorities develop specifications for installing hard shoulders on the left side of multi-lane freeways and adopt strategies to improve the traffic safety level of multi-lane freeways. In addition, the models and methods used in this paper can also help build a framework for future intelligent networked vehicle avoidance systems and promote the development of intelligent networked technologies.

Effect of Non-urban Two Lane Highway Geometry on Car and Bus Drivers – A Physiological Study

Life is a complex phenomenon, so is the task of driving. Mostly human performance is controlled by sympathetic and parasympathetic systems functioning in human body. It is quite dynamic in response to numerous stimuli the driver acquires from the human-vehicle-environmental ensemble. Geometry is one of the fundamental stimulus for a driver, driving on a non-urban highway, especially when there is minimal interference from other vehicles. Consequently, it is quite natural that drivers adopt higher speeds. His/her mental workload will be based on the input he/she gets from the above system and the rate of reception of input will be more with speed. Any inability to cope with the workload may lead to occurrence of crashes. Hence, it is very important to take into account the influence of geometry on driver workload while designing highways. One way to assess the workload is to capture the physiological responses of a driver like heart rate, galvanic skin resistance and rate of eye blinking, during driving.The study included driving experiments done on 114 horizontal curves of gradient less than 2 percentage, each curve being driven over by 30 car and bus drivers. The effect of geometry on workload of car and bus drivers were further analysed. It was found that driver physical characteristics like, age, driving experience, depth perception, vision acuity and reaction time were not found to significantly influence the workload. But workloads of car and bus drivers are significantly different. Sight distance and width of shoulder affect the workload of car drivers. Sight distance was the significant variable affecting bus driver workload. Workload of a driver is found to increase with increase in visibility as increased visual sensations actuates more physiological responses on a human body.

The impact of public–private partnerships for roadway projects on traffic safety: An exploratory empirical analysis of crash frequencies

Since the mid-2000s, Public–Private Partnerships (PPP) have been established in transportation infrastructure projects as an effective alternative to the traditional procurement process, such as design-bid-build where the design and construction are awarded separately and sequentially to private firms. PPP contracts ensure both greater participation of the private sector, as well as shared responsibility in project delivery. However, the interrelationship between various PPP approaches and the status of traffic safety during the project implementation has not been thoroughly explored to date. This paper seeks to provide new insights into the performance of different PPP contracting approaches by investigating them from the perspective of transportation safety. To that end, a statistical analysis is conducted in order to distinguish differences with respect to the characteristics of crashes that occurred during the contractual period of roadway projects. Using data from 645 PPP contracts that were executed across multiple States of the US between 1996 and 2011, count data models of crash frequencies are developed. To take into account the effect of unobserved factors on crash frequencies, correlated random parameter models with heterogeneity in the means are estimated. The results of the statistical analysis overall show that the determinants of crash frequencies and the magnitude of their impacts vary across PPP types. Contracts with higher cost, shorter duration, fewer lane-miles to be covered, more asset work activities, as well as contracts for roadways featuring better pavement and drainage conditions, low to medium AADT, and higher width of shoulder are more likely to observe fewer crashes. Additionally, several variables resulted in correlated random parameters (such as, contract size in lane-miles and truck percentage), with their distributional characteristics being affected by other exogenous factors (such as pavement characteristics), thus unveiling the heterogeneous patterns underpinning the safety performance of different PPP approaches.

Development of models to study traffic accidents on the final sections of access roads to the cities: a case study of three major Iranian cities

The final sections of main access roads to the cities require especial attention as the frequency of accidents in these road sections are considerably higher than other parts of interurban roads. These road sections operate as an interface between the rural roads and urban streets. The previous researches available on this subject are limited and they have also mainly focused on a narrow range of factors contributing to the accidents in these areas. The main contribution of this research is to consider a relatively comprehensive range of potential factors , and to examine their impacts through the development and comparison of both conventional probabilistic models and Artificial Neural Network (ANN) models. For this purpose, information related to the main access roads of three major Iranian cities were collected. This information consisted of accident frequency data together with the field observations of traffic characteristics, road-way conditions and roadside features of these roads. Various ANN and probabilistic models were developed. The frequency of accidents, i.e. fatal, injured, or damaged accidents, was considered as the output of the developed models. The results indicated that a hybrid of ANN models, each comprised of 10 input variables representing traffic, roadway and roadside conditions, outperformed several probabilistic models, i.e. Poisson, Negative binomial, Zero-truncated Poisson, and Zero-truncated Negative Binomial models, also developed under similar conditions in this study. Moreo-ver, effective roadway width, roadway lighting condition, the standard deviation of vehicles speed, percentage of drivers violating the speed limit, average annual daily traffic, percentage of heavy goods vehicles, the density of road-side commercial and industrial landuses, the density of median U-turns, the density of local access roads, and the effective width of the left-side shoulder were identified as the most effective factors contributing to the accidents in these areas. The developed ANN model can be used as a tool to predict accident rates in these road sections, and to estimate a potential reduction in the accident rates, following any improvements in the major factors contributing to the traffic accidents in these areas.

Feasibility Analysis of Runway, Taxiway and Apron Dimensions of Torea Airport in Fakfak Regency, West Papua Province

The development of transportation sector modes, especially air transportation modes, is currently experiencing a very significant development. This is because the mode of air transportation in the form of airplanes can make people move very quickly, unlike land and sea transportation modes which require a longer time. In this regard, an airport that meets the requirements in terms of flight security and safety is needed. The aim of the study was to analyze the dimensions of the runway, taxiway, appron and evaluate the feasibility of the runway, taxiway, appron dimensions at Torea Airport in Fakfak Regency, West Papua Province. From the results of the research conducted, it was found that the dimensions of the runway length of Torea Airport have met the minimum requirements set by the International Civil Aviation Organization (ICAO) in 2016 with a runway length of 1201.8 m Torea Airport but in terms of requirements for the type of aircraft ATR 72-600 does not meet the requirements. While for the standard dimensions of the runway width and the width of the runway shoulder of Torea Airport according to the Regulation of the Ministry of Transportation of the Directorate General of Civil Aviation Number: KP 39 of 2015 concerning Technical and Operational Standards of Civil Aviation Safety Regulations

Numerical Simulation and Optimization Design of End-Suspended Pile Support for Soil-Rock Composite Foundation Pit

In order to design the soil-rock combination foundation pit more safely and effectively, this paper presents the investigations of the mechanical and deformational characteristics of end-suspended piles supporting the structures in Jinan CBD area. Based on the measured data, a finite element model was established through the two-dimensional numerical simulation method to study the deformational characteristics of the end-suspended piles, and the influences of the depth of socketed rock, the width of rock shoulder, and the prestress of anchor cables on the deformations and mechanical property of end-suspended piles were discussed. Some optimization methods are proposed based on these analyses. Results show the following: (1) Rock-socketed depths have boundary effect on end-suspended piles. Under the given geological conditions, the reasonable socketed ratio is within 0.158∼0.200. (2) The anchor cable prestress can effectively slow down the ground settlement, the force, and deformation of the pile body and can be set to 1P∼1.25P under the conditions of the site. (3) Rock-shoulder width has little influence on the ground settlement and horizontal displacement of piles. The reserved width of rock shoulder is suggested to be selected in the range of 1.0 m∼1.5 m.

Evaluating Safety of Type-A Weaving Sections Using Geometric and Traffic Operational Factors

The efficiency and safety of type-A freeway weaving sections in urban areas are constrained by recurrent bottlenecks. Limited space in freeway weaving sections cause traffic congestion and crashes during peak-hours. Various factors, including length of weaving section, continuity of lanes, and number of lanes will have significant effects on the level of service and safety performance of the weaving sections. Eight years (2010-2017) of crash data in the type-A weaving sections was used in this analysis. The objective of this study aims to evaluate geometric design factors and operational factors on total crashes and each of the four crash types: rear-end, sideswipe, angle, and single-vehicle in type-A weaving sections using traditional negative binomial approach and develop crash modification factors (CMFs) to improve safety in the type-A weaving section. The results revealed that on-ramp traffic per hour, off-ramp traffic per hour, non-weaving traffic per hour, weaving ratio, length of the weaving section, direction of the freeway, width of inside shoulder, and width of outside shoulder were influencing crashes in type-A weaving sections. Furthermore, the estimated crash modification factors (CMFs) result revealed that total crashes gradually decrease as inside shoulder width increases. This implies that widening inside shoulder width have positive effects on weaving section safety. In addition, ramp metering, and advisory warning signs could improve safety in type-A weaving sections.

Investigating the influence of highway median design on driver stress

This study investigates the effect of highway median design on driver stress. Two types of highway medians were considered: a raised-curb median and a painted median. 80 drivers, equally distributed between males and females across two age groups (18–30 and 31–45 years old), were invited to participate in the experiment. Physiological changes in heart rate were measured, monitored and recorded before and during the driving test, and the diver perception survey method was also used to evaluate subjects perceived stress level while driving on different median types. For the divided highways with raised-curb median, the results from biometric measures as well as self-perception evaluations suggest that increasing the width of the inner shoulder could help to reduce the driver stress load. However, we found no effect from the width of the painted median, though this is probably due to low volumes of oncoming traffic during the experiment.

Effect of geometry on driver heart rate

Driving is a complex task incorporating most of the body organs and sensory system. Coordinated performance of eyes, ears, hands and legs are required in harmony with mental or cerebral actuations. Depending upon the stimulus the cardio vascular performance of a driver varies. The objective of this paper is to model the heart rate kinetics of drivers in response to variation in highway curve geometry. The study was done on 114 horizontal curves of two lane rural highways of Kerala. Heart rates of 30 drivers were collected during their drive along the study stretches. Cross sectional details of curve like radius of curve, length of curve, deflection angle, superelevation, width of road, width of shoulder and available sight distance were measured. Similarly the length of preceding tangent to the curve was also considered. Findings of the study revealed the correlation of sight distance and shoulder width with average heart rate. A nonlinear regression model was proposed based on analysis.

Temporary Traffic Control Strategy Optimization for Urban Freeways

Temporary traffic control (TTC) strategies have been widely adopted to maintain traffic flow while ensuring TTC costs remain a reasonable portion of construction budgets. As travel demand approaches the capacity of an existing facility, implementation of an appropriate TTC strategy is increasingly important not only because lane closures on these facilities exacerbate existing delay, but also because speeds associated with congestion contribute disproportionately and non-linearly to roadway emissions produced throughout the lifetime of the roadway. To enable stakeholders to make informed and transparent decisions on selecting a TTC strategy so as to balance the trade-offs among construction cost, traffic delay, and energy consumption, this paper discusses the development of an integrated model that identifies the Pareto-optimal front when construction start time, construction duration, lateral clearance, and width of shoulder borrowed as a through lane are considered as decision variables. A test implementation of the model suggests that when construction budgets are low, strategies for decreasing traffic delay differ significantly from those for decreasing energy consumption; however, as construction budgets increase, the objectives on traffic delay and energy consumption align much better.

Automatic human body feature extraction and personal size measurement

It is a pervasive problem to automatically obtain the size of a human body without contacting for applications like virtual try-on. In this paper, we propose a novel approach to calculate human body size, such as width of shoulder, girths of bust, hips and waist. First, a depth camera as the 3D model acquisition device is used to get the 3D human body model. Then an automatic extraction method of focal features on 3D human body via random forest regression analysis of geodesic distances is used to extract the predefined feature points and lines. Finally, the individual human body size is calculated according to these feature points and lines. The scale-invariant heat kernel signature is exploited to serve as feature proximity. So our method is insensitive to postures and different shapes of 3D human body. These main advantages of our method lead to robust and accurate feature extraction and size measurement for 3D human bodies in various postures and shapes. The experiment results show that the average error of feature points extraction is 0.0617cm, the average errors of shoulder width and girth are 1.332 cm and 0.7635 cm, respectively. Overall, our algorithm has a better detection effect for 3D human body size, and it is stable with better robustness than existing methods.

Investigation of hit-and-run crash occurrence and severity using real-time loop detector data and hierarchical Bayesian binary logit model with random effects

ABSTRACTObjective: Most of the extensive research dedicated to identifying the influential factors of hit-and-run (HR) crashes has utilized typical maximum likelihood estimation binary logit models, and none have employed real-time traffic data. To fill this gap, this study focused on investigating factors contributing to HR crashes, as well as the severity levels of HR.Methods: This study analyzed 4-year crash and real-time loop detector data by employing hierarchical Bayesian models with random effects within a sequential logit structure. In addition to evaluation of the impact of random effects on model fitness and complexity, the prediction capability of the models was examined. Stepwise incremental sensitivity and specificity were calculated and receiver operating characteristic (ROC) curves were utilized to graphically illustrate the predictive performance of the model.Results: Among the real-time flow variables, the average occupancy and speed from the upstream detector were observed to be positively correlated with HR crash possibility. The average upstream speed and speed difference between upstream and downstream speeds were correlated with the occurrence of severe HR crashes. In addition to real-time factors, other variables found influential for HR and severe HR crashes were length of segment, adverse weather conditions, dark lighting conditions with malfunctioning street lights, driving under the influence of alcohol, width of inner shoulder, and nighttime.Conclusions: This study suggests the potential traffic conditions of HR and severe HR occurrence, which refer to relatively congested upstream traffic conditions with high upstream speed and significant speed deviations on long segments. The above findings suggest that traffic enforcement should be directed toward mitigating risky driving under the aforementioned traffic conditions. Moreover, enforcement agencies may employ alcohol checkpoints to counter driving under the influence (DUI) at night. With regard to engineering improvements, wider inner shoulders may be constructed to potentially reduce HR cases and street lights should be installed and maintained in working condition to make roads less prone to such crashes.

Reasonable Transition form of Bridge-tunnel Connecting Section in Mountainous Expressway Affected by Crosswind

In order to explore a reasonable transition form of mountainous expressway in bridge-tunnel connecting section, driver's dynamic behavioural changes affected by crosswind is analysed through driving simulator. The experimental section is composed of tunnel and bridge, with different width of left shoulder. Driver's dynamic behaviour consists of two main parts: counter steering wheel angle and heart rate. The results show that the influence on driver's dynamic behaviour is greater when the car encountered crosswind at the exit of the tunnel than the crosswind suddenly disappearing at entry of incoming tunnel. As design speed is 100 kmph, the recommended value of left shoulder width is 1.5 m for tunnel exit, while 1.75 m for entrance. For the facility of design and construction, the theoretical transition form of bridge- tunnel connecting section is simplified.

A new structure for continuously reinforced concrete pavement with road performance evaluation

Due to the failure characteristics and imperfections of existing continuously reinforced concrete pavement (CRCP), a new CRCP structure is developed. The base course uses roller compacted concrete (RCC) over a gravel cushion. The surface layer is divided into two layers, where the upper layer is rubberized cement concrete, and the second layer is continuously reinforced concrete. An asphalt concrete layer is inserted between the base layer and the surface layer to act as an anti-scouring agent. Continuous longitudinal and transverse steel and sliding supports are placed on traffic lanes and inside half the width of the hard shoulder, the other half of the width being plain concrete. Using concepts from fracture mechanics, damage mechanics and numerical simulations, a study has been conducted to ascertain the damage and fracture of the asphalt overlay in the new structure. The results show that the fatigue damage lifetime of the overlay is substantially increased, while the crack propagation is greatly reduced. The new CRCP was successfully applied to a civil road engineering project and was shown to provide a notable economic benefit. Moreover, the new design can provide a theoretical basis for continuously reinforced concrete pavement and a useful reference for Chinese road development.

The effect of temperature, interaction range, and pair potential on the formation of dodecagonal quasicrystals in core-corona systems

A two-dimensional dodecagonal quasicrystal was previously reported by Dotera et al (2014 Nature 506 208) in a system of particles interacting with a hard core of diameter σ and a repulsive square shoulder of diameter . In the current work, we examine the formation of this quasicrystal using bond orientational order parameters, correlation functions and tiling distributions. We find that this dodecagonal quasicrystal forms from a fluid phase. We further study the effect of the width of the repulsive shoulder by simulating the system over a range of values of δ. For the range of densities and temperatures considered, we observe the formation of the dodecagonal quasicrystal between and . We also study the effect of shape of the interaction potential by simulating the system using three other interaction potentials with two length scales, namely hard-core plus a linear ramp, modified exponential, or Buckingham (exp-6) potential. We observe the presence of the quasicrystal in all three systems. However, depending on the shape of the potential, the formation of the quasicrystal takes place at lower temperatures (or higher interaction strengths). Using free-energy calculations, we demonstrate that the quasicrystal is thermodynamically stable in the square-shoulder and linear-ramp system.

Gender differences in joint torque focused on hip internal and external rotation during a change in direction while walking.

[Purpose] To investigate lower-extremity joint torque during walking direction changes, focused on gender differences in pelvic width. [Subjects and Methods] Healthy males and females (n=10) changed direction while walking by side-stepping (SS) and crossover stepping (CS), stepping the left leg to the left or right, respectively, over the right leg. Movements were recorded using four infrared cameras, and ground reaction force of each lower extremity measured using two force platforms. Joint torque of each lower extremity was calculated, and each joint peak torque among walking, SS and CS was compared between genders. Moreover, correlation between joint torque showed a gender difference and width of pelvis normalized by width of shoulder (P/S ratio) was examined. [Results] Right external and internal rotation torques during CS were higher in males. Left- and right-ankle plantar flexion torques were also higher in males during CS, while the P/S ratio was larger in females, with a positive correlation between P/S ratio and hip external and internal rotation torques. [Conclusion] No gender differences were found in joint torque during walking and SS, but only during CS. The hip external and internal rotators are necessary for smooth CS in females in terms of P/S ratio.

Car Drivers’ Experienced Level of Service on Freeways

The Danish Road Directorate sponsored a study to develop methods for quantifying car drivers’ experienced level of service on freeways. The results provide a measure of how well freeways accommodate car travel. To determine how traffic operations, geometric conditions, and other variables affect car drivers’ satisfaction, 188 randomly selected respondents were shown 80 video clips of roadway segments filmed from a driven passenger car. Video clips consisted of high-resolution video filmed through a windshield, side windows including exterior mirrors, and a rear window. Video clips also included a GPS-based speedometer. Respondents rated video clips on a six-point scale ranging from very satisfied to very dissatisfied. The result was 7,497 usable ratings. Four hundred to 450 variables described respondents’ answers to six background questions and the video clips, that is, roadway segment geometries, traffic operations, surroundings, weather, and so forth. Car driver satisfaction models were developed with cumulative logit regression and ordinary generalized linear modeling. The six presented models included three to 10 variables, which related significantly ( p ≤ .05) to satisfaction ratings. These variables were average speed, speed limit, width of hard shoulder, number of entries and other merge areas per mile, number of exits and other diverge areas per mile, flow of long vehicles per lane per hour, direction of sunlight, driver age, type of driver’s license, and driver yearly mileage. Models returned percentage splits of the six levels of satisfaction or average satisfaction. These splits or averages were transformed into a level of service.

MSP시험의 미세강도에 의한 FSW 최적용접설계

The usage of Friction Stir Welding(FSW) technology has been increasing in order to reduce the weight in automobile industries. Previous studies that investigated on the FSW have focused on the aluminum alloy. In this study, Al6061-T6 alloy plates having 5 mm of thickness were welded under nine different conditions from three tool rotation speeds: 900, 1000 and 1100 rpm, and three feed rates: 270, 300 and 330 mm/min. Specimen size of Micro Shear Punch(MSP) test was <TEX>$10{\times}10{\times}0.5mm$</TEX>. The mechanical properties were evaluated by MSP test and Analysis of Variance (ANOVA). The specimens were classified by advancing side(AS), retreating side(RS), and center(C) of width of tool shoulder. The optimal welding condition of FSW based on micro strengh was obtained when the tool rotation speed was 1100 rpm and the feed rate was 300 mm/min. The maximum load measured AS, RS, and C in the weldment was measured 554.7 N, 642.9 N, and 579.2 N, respectively.