Safety Evaluation of Freeway Alignment Case Analysis

2013 ◽  
Vol 779-780 ◽  
pp. 939-945
Author(s):  
Jiang Bi Hu ◽  
Xiang Zheng Chang ◽  
Jian Ping Cao
Keyword(s):  
Heart Rate ◽  
Healthy Adult ◽  
Safety Evaluation ◽  
Case Analysis ◽  
Truck Drivers ◽  
Operating Speed ◽  
Road Design ◽  
Driver Workload ◽  
Accident Data ◽  
Variability Index

Variation of driver workload degree on freeway was analyzed in order to research safe and comfort of alignment and provide a new technical support for humanization road design. A total of 12 healthy adult drivers heart rate variability index and operating speed are tested on 77 sections of one mountainous freeway. According to the change law of different drivers workload degree on different alignment conditions,4 sections cant meet the expectations of the truck drivers safe and comfort. In addition, accident data is used to verify the dangerous sections. Research results can be applied to design road alignment that meets the driving expectations of different drivers.

scholarly journals Effect of Two Lane Non-Urban Highway Geometry on Workload Profile of Drivers

2021 ◽  
Author(s):  
Jisha Akkara ◽  
Anitha Jacob ◽  
Subaida E A ◽  
Dona Joy ◽  
Sreelakshmi K S
Keyword(s):  
Heart Rate ◽  
Galvanic Skin Response ◽  
Safety Evaluation ◽  
Real Field ◽  
Radius Of Curvature ◽  
Safe Driving ◽  
Sight Distance ◽  
Skin Response ◽  
Driver Workload ◽  
The Government

Transportation engineers play an important role to achieve zero- crash vision of the Government. The onus for occurrence of road crashes at under-designed and poorly constructed roads lies on the shoulders of transportation engineers. To ensure safe and comfortable driving, it is essential and necessary to evaluate the geometric design of roads, especially highways, from the perspective of the vehicle drivers. If the road is of consistent design, the driver can achieve smooth and safe driving. Inconsistent design of roads can confuse a driver and it may lead to unnecessary speed changes and even may result in unfavourable level of crashes. This paper attempts to study how the highway geometry affects the driver workload at horizontal curves and curves with gradient on two lane non-urban highways. The driver workload is assessed by measuring variations in physiological conditions of subject driver while driving in a test car under real field conditions. Heart rate (HR) and galvanic skin response (GSR) of drivers are continuously recorded using sensors attached to the driver’s ear and fingers respectively to develop a continuous profile of driver workload at varying highway geometry. The variations in heart rate from tangent sections to succeeding curve sections are determined to understand the effect of curve geometry on heart rate. The geometrical data such as radius of curvature, superelevation, sight distance, gradient and tangent length are collected from the selected study stretches. The study revealed that the inconsistent design of roads leads to large variations in heart rate and galvanic skin response. Consequently, crash frequency is found to be higher at such locations. The outcome of the study will help highway designers to design safer roads. The outcome of the study throws light on safety evaluation of highway geometry and will be helpful in developing tools and guidelines for designing safer roads.

Comparison between Powered Two-Wheeler and Passenger Car Free-Flow Speeds in Urban Areas

2008 ◽  
Vol 2074 (1) ◽  
pp. 77-84 ◽  
Author(s):  
Paolo Perco
Keyword(s):  
Traffic Safety ◽  
Urban Areas ◽  
Prediction Equation ◽  
Performance Measure ◽  
Operating Speed ◽  
Design Standards ◽  
Passenger Car ◽  
Road Design ◽  
Flow Speeds ◽  
Accident Data

Accident data indicate that motorcyclists are a particularly vulnerable group of road users because they run a higher risk of being injured or killed in an accident than passenger car drivers. One of the countermeasures that can improve traffic safety for motorcyclists is an increase in awareness and knowledge about powered two-wheelers (PTWs) in the planning, construction, operation, and maintenance of new and existing roads. Road design standards and policies that regulate design process and safety evaluations are usually based on passenger car characteristics only. In particular, the passenger car operating speed is used as the critical input for design choices of geometric elements connected with traffic safety and as a performance measure to evaluate road design and consistency. Because the passenger car operating speed might not be representative of the PTW operating speed, this study compared the PTW and passenger car speed distributions in urban areas to establish definitively whether they are similar. The results showed that PTW speeds are always considerably higher than passenger car speeds and that the corresponding operating speeds are correlated. Therefore, a prediction equation to estimate the PTW operating speed starting from passenger car operating speed was developed for urban streets. This equation can help highway engineers to estimate expected PTW speeds that can be effectively used in the safety evaluations of new and existing roads where the significant presence of PTWs in the traffic flow suggests that this vehicle type should be considered.

scholarly journals A Novel Approach for Operating Speed Continuous Predication Based on Alignment Space Comprehensive Index

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Ying Yan ◽  
Gengping Li ◽  
Jinjun Tang ◽  
Zhongyin Guo
Keyword(s):  
Field Experiments ◽  
Prediction Models ◽  
Three Dimensional ◽  
Safety Evaluation ◽  
Driving Safety ◽  
Operating Speed ◽  
Passenger Cars ◽  
Comprehensive Index ◽  
Novel Approach ◽  
Lane Width

Operating speed is a critical indicator for road alignment consistency design and safety evaluation. Although extensive studies have been conducted on operating speed prediction, few models can finish practical continuous prediction at each point along alignment on multilane highways. This study proposes a novel method to estimate the operating speed for multilane highways in China from the aspect of the three-dimensional alignment combination. Operating speed data collected in field experiments on 304 different alignment combination sections are detected by means of Global Positioning System. First, the alignment comprehensive index (ACI) is designed and introduced to describe the function accounting for alignment continuity and driving safety. The variables used in ACI include horizontal curve radius, change rate of curvature, deflection angle of curve, grade, and lane width. Second, the influence range of front and rear alignment on speed is determined on the basis of drivers’ fixation range and dynamical properties of vehicles. Furthermore, a prediction model based on exponential relationships between road alignment and speeds is designed to predict the speed of passenger cars and trucks. Finally, three common criteria are utilized to evaluate the effectiveness of the prediction models. The results indicate that the prediction models outperform the other two operating speed models for their higher prediction accuracy.

Risk Analysis Techniques for Safety Evaluation of Highway Work Zones

2000 ◽  
Vol 1715 (1) ◽  
pp. 10-17 ◽  
Author(s):  
Ana Maria Elias ◽  
Zohar J. Herbsman
Keyword(s):  
Risk Analysis ◽  
Safety Evaluation ◽  
Highway Safety ◽  
Point Of View ◽  
Work Zone ◽  
Work Zones ◽  
Construction Sites ◽  
Work Zone Safety ◽  
Accident Data ◽  
Temporary Closure

Construction sites or work zones create serious disruptions in the normal flow of traffic, resulting in major inconveniences for the traveling public. Furthermore, these work zones create safety hazards that require special consideration. Current legislation and programs, at both state and national levels, emphasize the need for a better understanding of work zone problems to address work zone safety. This reality—coupled with the temporary closure of more miles of highway every year for rehabilitation and maintenance—makes the analysis of safety at construction sites a serious matter. A summary of a comprehensive study associated with the development of a new practical approach to address highway safety in construction zones is presented. Because empirical models require sample sizes that are not attainable due to the intrinsic scarcity of construction zone accident data, the problem was studied from the point of view of risk analysis. Monte Carlo simulations were used to develop risk factors. These factors are meant to be included in the calculations of additional user costs for work zones, or simply applied as risk measurements, to optimize the length and duration of closures for highway reconstruction and rehabilitation projects. In this way, it will be possible to assess the danger of work zones to the traveling public and minimize adverse effect of work zones on highway safety.

Research on Tunnel Interior Zone Luminance Evaluation Method and its Application

2013 ◽  
Vol 779-780 ◽  
pp. 929-934
Author(s):  
Jing Bi Hu ◽  
Da Guo ◽  
Xiao Qin Zhang
Keyword(s):  
South China ◽  
Evaluation Method ◽  
Operating Speed ◽  
Safe Operation ◽  
Luminance Threshold ◽  
Traffic Environment ◽  
Interior Zone ◽  
Driver Workload ◽  
Driving Workload ◽  
Driving Fatigue

Because of the special traffic environment, the tunnel is called a bottleneck on the highway sections; there is a huge risk of safe operation. Tunnel interior zone lighting plays an important role in the tunnel; good lighting can eliminate depression and driving fatigue of the driver in the tunnel. In this paper, freeway tunnel interior zone lighting is as the research object. We analyzed the driver's demand for freeway tunnel interior zone lighting and transformed illumination to luminance in the model of driver workload, operating speed and the illumination. And this model is established by our group. According to comfortable and relatively comfortable driving workload intense threshold, we can get the safe and comfortable luminance threshold of tunnel interior zone. This paper proposed a detection and evaluation method in freeway tunnel interior zone luminance, and the method have been applied and verified on one freeway in south China.

scholarly journals Heart Rate Correction of the J-to-Tpeak Interval

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Katerina Hnatkova ◽  
Jose Vicente ◽  
Lars Johannesen ◽  
Christine Garnett ◽  
David G. Strauss ◽  
...  
Keyword(s):  
Heart Rate ◽  
Safety Evaluation ◽  
Linear Regression Models ◽  
Drug Induced ◽  
Rr Intervals ◽  
Channel Effects ◽  
Linear Correction ◽  
History Of ◽  
Heart Rate Correction ◽  
Log Linear

Abstract Drug-induced changes of the J to T peak (JTp) and J to the median of area under the T wave (JT50) were reported to differentiate QT prolonging drugs that are predominant blockers of the delayed potassium rectifier current from those with multiple ion channel effects. Studies of drug-induced JTp/JT50 interval changes might therefore facilitate cardiac safety evaluation of new pharmaceuticals. It is not known whether formulas for QT heart rate correction are applicable to JTp and JT50 intervals. QT/RR, JTp/RR, and JT50/RR profiles were studied in 523 healthy subjects aged 33.5 ± 8.4 years (254 females). In individual subjects, 1,256 ± 220 electrocardiographic measurements of QT, JTp, and JT50 intervals were available including a 5-minute history of RR intervals preceding each measurement. Curvilinear, linear and log-linear regression models were used to characterize individual QT/RR, JTp/RR, and JT50/RR profiles both without and with correction for heart rate hysteresis. JTp/RR and JT50/RR hysteresis correction needs to be included but the generic universal correction for QT/RR hysteresis is also applicable to JTp/RR and JT50/RR profiles. Once this is incorporated, median regression coefficients of the investigated population suggest linear correction formulas JTpc = JTp + 0.150(1-RR) and JT50c = JT50 + 0.117(1-RR) where RR intervals of the underlying heart rate are hysteresis-corrected, and all measurements expressed in seconds. The established correction formulas can be proposed for future clinical pharmacology studies that show drug-induced heart rate changes of up to approximately 10 beats per minute.

Cardiopulmonary Effects of Intrathoracic Insufflation in Dogs

2002 ◽  
Vol 38 (6) ◽  
pp. 515-520 ◽  
Author(s):  
Curt M. Daly ◽  
Karen Swalec-Tobias ◽  
Anthony H. Tobias ◽  
Nicole Ehrhart
Keyword(s):  
Heart Rate ◽  
Cardiac Output ◽  
Arterial Pressure ◽  
Healthy Adult ◽  
Venous Pressure ◽  
Minute Volume ◽  
Mechanical Ventilator ◽  
Central Venous ◽  
Anesthetized Dogs ◽  
Pressure Standard

This study was designed to quantify the effects of incremental positive insufflation of the intrathoracic space on cardiac output (CO), heart rate (HR), arterial pressure (AP), central venous pressure (CVP), and percent saturation of hemoglobin with oxygen (SPO2) in anesthetized dogs. Seven healthy, adult dogs from terminal teaching laboratories were maintained under anesthesia with isoflurane delivered with a mechanical ventilator. The experimental variables were recorded before introduction of an intrathoracic catheter, at intrathoracic pressures (IP) of 0 mm Hg, 3 mm Hg insufflation, and additional increments of 1 mm Hg insufflation thereafter until the SPO2 remained <85% despite increases in minute volume. Finally the variables were measured again at 0 mm Hg IP. The cardiac output and systolic and diastolic AP significantly (P<0.05) decreased at 3 mm Hg IP. Significant decreases in SPO2 were seen at 10 mm Hg IP. Significant increase in CVP was noted at 6 mm Hg IP. Heart rate decreased significantly at 5 to 6 mm Hg IP but was not decreased above 6 mm Hg IP. Given the degree of CO decrease at low intrathoracic pressures, insufflation-aided thoracoscopy should be used with caution and at the lowest possible insufflation pressure. Standard anesthetic monitoring variables such as HR and AP measurements may not accurately reflect the animal’s cardiovascular status.

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