scholarly journals Crash- and Simulation-Based Safety Performance Evaluation of Freeway Rest Area

2021 ◽  
Vol 13 (9) ◽  
pp. 4963
Author(s):  
Hyeonseo Kim ◽  
Kyeongjoo Kwon ◽  
Nuri Park ◽  
Juneyoung Park ◽  
Mohamed Abdel-Aty
Keyword(s):  
Safety Performance ◽  
Safety Performance Function ◽  
Traffic Conditions ◽  
Link Functions ◽  
Simulation Based ◽  
Modification Factor ◽  
Rest Areas ◽  
Nonlinear Trends ◽  
Performance Results ◽  
Surrogate Safety Measures

The main objective of this study was to evaluate the safety effects caused by altering the lengths of deceleration and acceleration lanes at rest areas on expressways in Korea. Although general conclusions can be found through crash-based safety analysis, to examine more specific optimal conditions considering various traffic conditions, this study proposes a novel framework to explore and evaluate crash-based and simulation-based safety performances. For this purpose, the safety performance function (SPF) and crash modification factor (CMF) were developed to reflect real-world safety impacts. To consider nonlinear trends of the parameters, nonlinearizing link functions were introduced into the analysis. Two types of simulation analyses were conducted to (1) find the combination of surrogate safety measures (SSMs) that best fit with the crash-based safety performance results and (2) determine the optimal lengths of deceleration lane and acceleration lanes for different traffic conditions. The results showed that the best length of deceleration lane of a rest area is between 240 and 260 m, depending on the traffic conditions. The results also indicated that the optimal length of acceleration lane of a rest area is between 385 and 400 m, depending on the traffic parameters. The findings of this study could be used to determine the safety solutions with a micro-traffic simulator.

scholarly journals Evaluating Fatigue, Stress, Workload and Situation Awareness Among Electrical Substation Construction Workers

2020 ◽  
Vol 6 (1) ◽  
pp. 1
Author(s):  
Ahmed Ali Bayounis ◽  
Abdulrahman Basahel
Keyword(s):  
Situation Awareness ◽  
Construction Projects ◽  
Safety Management ◽  
Safety Performance ◽  
Working Environment ◽  
Western Area ◽  
Job Levels ◽  
Electrical Substation ◽  
Performance Results ◽  
Stress Fatigue

Many accidents occur due to various factors when undertaking construction projects. One of the most important achievements when undertaking a construction project is to accomplish the project without major accidents. This paper studies the effect of stress, fatigue and workload on construction contract worker in term of their safety performance results using the Situation Awareness Rating Technique (SART), with reference to how it relates to the root causes of accidents. Investigating the factors associated with accidents helps to identify and minimize the associated mistakes or causes and reduce or avoid accidents and improve safety performance in construction projects. Data were collected using a SART survey of employee of 18 contractors working on construction of electrical substations in the western area of Saudi Arabia. It was found that most accidents occurred at the worker level because of their lack of awareness and training. It is apparent that SART affects the safety performance of contractors and it varies with the position, age and experience of workers. To implement a safe working environment free of accidents, it is necessary to improve all job levels according to their insufficient area and activate a full safety management system with periodic reviews to improve it and make it more effective.

How the choice of safety performance function affects the identification of important crash prediction variables

2016 ◽  
Vol 88 ◽  
pp. 1-8 ◽  
Author(s):  
Ketong Wang ◽  
Jenna K. Simandl ◽  
Michael D. Porter ◽  
Andrew J. Graettinger ◽  
Randy K. Smith
Keyword(s):  
Safety Performance ◽  
Performance Function ◽  
Crash Prediction ◽  
Safety Performance Function

scholarly journals Proposing New Methods to Estimate the Safety Level in Different Parts of Freeway Interchanges

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Hamid Behbahani ◽  
Sayyed Mohsen Hosseini ◽  
Alireza Taherkhani ◽  
Hemin Asadi ◽  
Seyed Alireza Samerei
Keyword(s):  
Video Processing ◽  
Prediction Models ◽  
Trajectory Data ◽  
Safety Level ◽  
Accident Prediction ◽  
Traffic Characteristics ◽  
Potential Index ◽  
Simulation Based ◽  
Surrogate Safety Measures ◽  
Different Parts

Since attention to the safety of traffic facilities including freeway interchanges has been increased during recent years, accident prediction models are being developed. Simulation-based surrogate safety measures (SSMs) have been used in the absence of real collision data. But, obtaining different outputs from different SSMs as safety indicators had led to a complexity of using them as the collision avoidance system basis. Additionally, applying SSM requires trajectory data which can be hardly obtained from video processing or calibrated microsimulations. Estimating safety level in different parts of freeway interchanges through a new proposed method was considered in this paper. Fuzzy logic was applied to combine the outputs of different SSMs, and an index called no-collision potential index (NCPI) was defined. 13608 calibrated simulations were conducted on different ramps, weaving, merge, and diverge areas with different geometrical and traffic characteristics, and NCPI was determined for every case. The geometrical and traffic characteristics formed input data of two safety estimator models developed by Artificial Neural Network and Particle Swarm Optimization. Ten freeway interchanges were investigated to calibrate the simulations and to ensure the validity of the fuzzy method and accuracy of the models. Results showed an appropriate and accurate development of the models.

scholarly journals PEDESTRIAN SAFETY EVALUATION OF SIGNALIZED INTERSECTIONS USING SURROGATE SAFETY MEASURES

Transport ◽  
2020 ◽  
Vol 35 (1) ◽  
pp. 48-56
Author(s):  
Sankaran Marisamynathan ◽  
Perumal Vedagiri
Keyword(s):  
Safety Evaluation ◽  
Pedestrian Safety ◽  
Signalized Intersections ◽  
Signalized Intersection ◽  
Mixed Traffic ◽  
Model Framework ◽  
Safety Measures ◽  
Severity Level ◽  
Traffic Conditions ◽  
Surrogate Safety Measures

The large proportions of pedestrian fatalities led researchers to make the improvements of pedestrian safety at intersections. Thus, this paper proposes a methodology to evaluate crosswalk safety at signalized intersections using Surrogate Safety Measures (SSM) under mixed traffic conditions. The required pedestrian, traffic, and geometric data were extracted based on the videographic survey conducted at signalized intersections in Mumbai (India). Post Encroachment Time (PET) for each pedestrian were segregated into three categories for estimating pedestrian–vehicle interactions and Cumulative Frequency Distribution (CDF) was plotted to calculate the threshold values for each interaction severity level. The Cumulative Logistic Regression (CLR) model was developed to predict the pedestrian mean PET values in the cross-walk at signalized intersections. The proposed model was validated with a new signalized intersection and the results were shown that the proposed PET ranges and model appropriate for Indian mixed traffic conditions. To assess the suitability of model framework, model transferability was carried out with data collected at signalized intersection in Kolkata (India). Finally, this study can be helpful to rank the severity level of pedestrian safety in the crosswalk and improve the existing facilities at signalized intersections.

scholarly journals Segmentation Effect on the Transferability of International Safety Performance Functions for Rural Roads in Egypt

Safety ◽  
2020 ◽  
Vol 6 (3) ◽  
pp. 43
Author(s):  
Sania Reyad Elagamy ◽  
Sherif M. El-Badawy ◽  
Sayed A. Shwaly ◽  
Zaki M. Zidan ◽  
Usama Elrawy Shahdah
Keyword(s):  
Constant Term ◽  
Safety Performance ◽  
Likelihood Method ◽  
Percentage Error ◽  
Segmentation Method ◽  
Local Data ◽  
Absolute Deviation ◽  
Rural Roads ◽  
Safety Performance Function ◽  
Segmentation Approach

This paper examines the transferability of the Safety Performance Function (SPF) of the Highway Safety Manual (HSM) and other 10 international SPFs for total crashes on rural multi-lane divided roads in Egypt. Four segmentation approaches are assessed in the transferability of the international SPFs, namely: (1) one-kilometer segments (S1); (2) homogenous sections (S2); (3) variable segments with respect to the presence of curvatures (S3); and (4) variable segments with respect to the presence of both curvatures and U-turns (S4). The Mean Absolute Deviation (MAD), Mean Prediction Bias (MPB), Mean Absolute Percentage Error (MAPE), Pearson χ2 statistic, and Z-score parameters are used to evaluate the performance of the transferred models. The overdispersion parameter (k) for each transferred model and each segmentation approach is recalibrated using the local data by the maximum likelihood method. Before estimating the transferability calibration factor (Cr), three methods were used to adjust the local crash prediction of the transferred models, namely: (1) the HSM default crash modification factors (CMFs); (2) local CMFs; and (3) recalibrating the constant term of the transferred model. The latter method is found to outperform the first two methods. Besides, the results show that the segmentation method would affect the performance of the transferability process. Moreover, the Italian SPFs based on the S1 segmentation method outperforms the HSM and all of the investigated international SPFs for transferring their models to the Egyptian rural roads.

Impact of Risk-Taking Attitudes on Performance Appraisal

1982 ◽  
Vol 51 (3_suppl) ◽  
pp. 1139-1147
Author(s):  
David W. Grigsby ◽  
Terry L. Leap
Keyword(s):  
Performance Appraisal ◽  
Risk Taking ◽  
Simulation Based ◽  
Performance Results

This simulation-based study was done to determine whether the attitudes of raters and ratees toward risk affect appraisals of performance. Results indicate that raters employ a congruency model whereby ratees having attitudes toward risk similar to the raters' own attitudes are assigned higher ratings than those having dissimilar attitudes toward risk.

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