Pub Date : 2021-12-31DOI: 10.5604/01.3001.0015.6030
R. Żochowska, Adrian Barchański
The efficiency of the entire transportation system depends on the capacity of the individual elements that make up the given network. Point-type elements of the road and street network include intersections of different types. Critical gaps and follow-up times related to individual movements are important determinants of the capacity of such objects. There are many ways to estimate such times. The article discusses the assumptions and scheme one of them - the Siegloch method. The objective of the article is to analyze the process of determining critical gaps and follow-up times at the median uncontrolled T-intersections that are rare in the road and street network and have been studied to a limited extent. The commonly used HCM, HBS, and Polish (MOP SBS) methods in their current form do not consider the speci-ficity of such intersections and thus may not give reliable results. Due to their characteristics in terms of geometry conditions, there is a need for an individual approach to estimate both critical gaps and follow-up times. The article contains the results of empirical research conducted on a selected real object in the Upper Silesian agglomeration in Poland. The intersection under study is located in one of the central districts of Katowice city, in the built-up area serving commercial and service functions. The analysis of the behavior of individual drivers waiting for the possibility to continue driving was conducted separately for each minor traffic movement. The values of critical gaps and follow-up times were determined for all four subordinate movements. The values obtained are different from those contained in the Polish manual, which is recommended for use. The research should be considered as pilot studies that justify the need to develop a separate approach to the estimation of the critical gaps and follow-up times at median uncontrolled T-intersections.
{"title":"Estimation of critical gaps and follow-up times at median uncontrolled T-intersection","authors":"R. Żochowska, Adrian Barchański","doi":"10.5604/01.3001.0015.6030","DOIUrl":"https://doi.org/10.5604/01.3001.0015.6030","url":null,"abstract":"The efficiency of the entire transportation system depends on the capacity of the individual elements that make up the given network. Point-type elements of the road and street network include intersections of different types. Critical gaps and follow-up times related to individual movements are important determinants of the capacity of such objects. There are many ways to estimate such times. The article discusses the assumptions and scheme one of them - the Siegloch method. The objective of the article is to analyze the process of determining critical gaps and follow-up times at the median uncontrolled T-intersections that are rare in the road and street network and have been studied to a limited extent. The commonly used HCM, HBS, and Polish (MOP SBS) methods in their current form do not consider the speci-ficity of such intersections and thus may not give reliable results. Due to their characteristics in terms of geometry conditions, there is a need for an individual approach to estimate both critical gaps and follow-up times. The article contains the results of empirical research conducted on a selected real object in the Upper Silesian agglomeration in Poland. The intersection under study is located in one of the central districts of Katowice city, in the built-up area serving commercial and service functions. The analysis of the behavior of individual drivers waiting for the possibility to continue driving was conducted separately for each minor traffic movement. The values of critical gaps and follow-up times were determined for all four subordinate movements. The values obtained are different from those contained in the Polish manual, which is recommended for use. The research should be considered as pilot studies that justify the need to develop a separate approach to the estimation of the critical gaps and follow-up times at median uncontrolled T-intersections.\u0000\u0000","PeriodicalId":53541,"journal":{"name":"Archives of Transport","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41327873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.5604/01.3001.0015.3275
Marek Kisilowski, K. Stypulkowski
The article aims to preliminary analyze and identify the working conditions of an operator wearing disposable personal protective equipment and features and usability of the suit. The characteristics of the thermal image for an operator wearing a personal protection suit will be used as part of the IT system for comfort assessment. The system will allow the assessment of the operator's comfort based on thermograms. It will also detect dangerous situations resulting from the operator's work in such an outfit or overalls. The hazardous conditions for operators are related to the symptoms of thermal discomfort leading to overheating the body and, consequently, fainting. These situations may cause accidents and reduce the quality of the activities performed. The current legal status was considered when referring to selected social aspects in the management and quality of work of an operator wearing a COVID-19 protective suit. References are made to documents on legislative acts in Poland and Europe to limit the risk from biological agents. This part of the article refers to a vital study by Majchrzycka and Okrasa (2019, the Central Institute for Labor Protection - National Research Institute) presenting the rules for the safe use of non-biocidal respiratory protective equipment. This included obligations of the employer. The employer is obliged to take preventive measures against exposition of employees to harmful biological agents, including airtight measures and personal protective equipment. The article emphasizes selected medical aspects of working in personal protective clothing during the COVID-19 pandemic. Referring to the study (Sobolewski, 2014), according to the authors, the presented case reflects the working conditions of an operator wearing a disposable protective suit. Microclimate parameters and changing metabolism define the hot thermal environment in the mentioned standard. The article presents the results of thermovision inspection of the operator of technical means of transport working in a suit protecting against COVID-19 infection, constituting one-off personal protection. The individual elements included in the protective set of disposable personal protection have been described. The following research stage is preparing thermograms, which show the operator in a protective case before, during, and after work. Thermograms have been classified and commented on.
{"title":"Thermal imaging for the operator's comfort assessment in the aspect of the COVID-19 pandemic","authors":"Marek Kisilowski, K. Stypulkowski","doi":"10.5604/01.3001.0015.3275","DOIUrl":"https://doi.org/10.5604/01.3001.0015.3275","url":null,"abstract":"The article aims to preliminary analyze and identify the working conditions of an operator wearing disposable personal protective equipment and features and usability of the suit. The characteristics of the thermal image for an operator wearing a personal protection suit will be used as part of the IT system for comfort assessment. The system will allow the assessment of the operator's comfort based on thermograms. It will also detect dangerous situations resulting from the operator's work in such an outfit or overalls. The hazardous conditions for operators are related to the symptoms of thermal discomfort leading to overheating the body and, consequently, fainting. These situations may cause accidents and reduce the quality of the activities performed. The current legal status was considered when referring to selected social aspects in the management and quality of work of an operator wearing a COVID-19 protective suit. References are made to documents on legislative acts in Poland and Europe to limit the risk from biological agents. This part of the article refers to a vital study by Majchrzycka and Okrasa (2019, the Central Institute for Labor Protection - National Research Institute) presenting the rules for the safe use of non-biocidal respiratory protective equipment. This included obligations of the employer. The employer is obliged to take preventive measures against exposition of employees to harmful biological agents, including airtight measures and personal protective equipment. The article emphasizes selected medical aspects of working in personal protective clothing during the COVID-19 pandemic. Referring to the study (Sobolewski, 2014), according to the authors, the presented case reflects the working conditions of an operator wearing a disposable protective suit. Microclimate parameters and changing metabolism define the hot thermal environment in the mentioned standard. The article presents the results of thermovision inspection of the operator of technical means of transport working in a suit protecting against COVID-19 infection, constituting one-off personal protection. The individual elements included in the protective set of disposable personal protection have been described. The following research stage is preparing thermograms, which show the operator in a protective case before, during, and after work. Thermograms have been classified and commented on.\u0000\u0000","PeriodicalId":53541,"journal":{"name":"Archives of Transport","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47063378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.5604/01.3001.0014.9553
Zsófia Magyari, C. Koren, M. Kiec, A. Borsos
Many traffic accidents are caused by unforeseen and unexpected events in a site that was hidden from the driver's eyes. Road design parameters determining required visibility are based on relationships formulated decades ago. It is worth reviewing them from time to time in the light of technological developments. In this paper, sight distances for stopping and crossing situations are studied in relation to the assumed visual abilities of autonomous vehicles. Current sight distance requirements at unsignalized intersections are based among others on speeds on the major road and on ac-cepted gaps by human drivers entering or crossing from the minor road. Since these requirements vary from country to country, regulations and sight terms of a few selected countries are compared in this study. From the comparison it is remarkable that although the two concepts, i.e. gap acceptance on the minor road and stopping on the major road have different backgrounds, but their outcome in terms of required sight distances are similar. Both distances are depending on speed on the major road: gap sight distances show a linear, while stopping sight distances a parabolic function. In general, European SSD values are quite similar to each other. However, the US and Australian guidelines based on gap acceptance criteria recommend higher sight distances. Human capabilities and limitations are considered in sight field requirements. Autonomous vehicles survey their environment with sensors which are different from the human vision in terms of identifying objects, estimating distances or speeds of other vehicles. This paper compares current sight field requirements based on conventional vehicles and those required for autonomous vehicles. Visibility requirements were defined by three vision indicators: distance, angle of view and resolution abilities of autonomous cars and human drivers. These indicators were calculated separately for autonomous vehicles and human drivers for various speeds on the main road and for intersections with 90° and 60° angles. It was shown that the required sight distances are 10 to 40 meters shorter for autonomous vehicles than for conventional ones.
{"title":"Sight distances at unsignalized intersections: a comparison of guidelines and requirements for human drivers and autonomous vehicles","authors":"Zsófia Magyari, C. Koren, M. Kiec, A. Borsos","doi":"10.5604/01.3001.0014.9553","DOIUrl":"https://doi.org/10.5604/01.3001.0014.9553","url":null,"abstract":"Many traffic accidents are caused by unforeseen and unexpected events in a site that was hidden from the driver's eyes. Road design parameters determining required visibility are based on relationships formulated decades ago. It is worth reviewing them from time to time in the light of technological developments. In this paper, sight distances for stopping and crossing situations are studied in relation to the assumed visual abilities of autonomous vehicles. Current sight distance requirements at unsignalized intersections are based among others on speeds on the major road and on ac-cepted gaps by human drivers entering or crossing from the minor road. Since these requirements vary from country to country, regulations and sight terms of a few selected countries are compared in this study. From the comparison it is remarkable that although the two concepts, i.e. gap acceptance on the minor road and stopping on the major road have different backgrounds, but their outcome in terms of required sight distances are similar. Both distances are depending on speed on the major road: gap sight distances show a linear, while stopping sight distances a parabolic function. In general, European SSD values are quite similar to each other. However, the US and Australian guidelines based on gap acceptance criteria recommend higher sight distances. Human capabilities and limitations are considered in sight field requirements. Autonomous vehicles survey their environment with sensors which are different from the human vision in terms of identifying objects, estimating distances or speeds of other vehicles. This paper compares current sight field requirements based on conventional vehicles and those required for autonomous vehicles. Visibility requirements were defined by three vision indicators: distance, angle of view and resolution abilities of autonomous cars and human drivers. These indicators were calculated separately for autonomous vehicles and human drivers for various speeds on the main road and for intersections with 90° and 60° angles. It was shown that the required sight distances are 10 to 40 meters shorter for autonomous vehicles than for conventional ones.\u0000\u0000","PeriodicalId":53541,"journal":{"name":"Archives of Transport","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49556928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.5604/01.3001.0014.9554
P. Tomczuk, M. Chrzanowicz, Tomasz Mackun, M. Budzynski
The night time, based on many world studies, generates an increased risk of serious accidents (with fatalities and serious injuries). This is especially true for accidents with pedestrians. Pedestrian crossings are very sensitive to the influence of the time of day in terms of pedestrian safety, elements of road infrastructure. This is visible on the example of Poland, where numerous accidents at crosswalks are recorded, characterized by high severity at night. Road infra-structure managers take corrective actions to improve this condition. An example of such work is the Road Safety Audit (RSA), initiated in 2016 by the Municipal Roads Management Board in Warsaw. The analyses carried out by the au-thors, among others, in the years 2016 - 2019, included pedestrian crossings without traffic lights located on roads managed by ZDM (Municipal Roads Authority) in twelve districts: Bemowo, Bielany, Mokotów, Ochota, Praga Połud-nie, Praga Północ, Śródmieście, Targówek, Ursynów, Wawer, Włochy, Żoliborz. The assessment was carried out in terms of the correct lighting of these passages, traffic organization, geometry and environmental impact. The main aim of the article is to present a methodology for evaluating the technical condition of road lighting infrastructure on a large scale (e.g. district, city). The article discusses the general and detailed state of pedestrian safety in Poland against the background of research conducted in Warsaw. The procedure of inspection and assessment of the state of lighting of pedestrian crossings is described and selected results are presented. On the basis of a detailed analysis of the results of individual pedestrian crossings, the general condition of the tested crossings was assessed and recommendations were indicated. An attempt was made to assess the influence of pedestrian crossings lighting on the general state of road safety. A critical evaluation of the obtained effects was made. The utilitarian aim of the article is to apply the described methodology in other cities and to use the results of the conducted analyses to plan and implement road investments in the field of modernization of lighting at pedestrian crossings on a large scale.
{"title":"Analysis of the results of the audit of lighting parameters at pedestrian crossings in Warsaw","authors":"P. Tomczuk, M. Chrzanowicz, Tomasz Mackun, M. Budzynski","doi":"10.5604/01.3001.0014.9554","DOIUrl":"https://doi.org/10.5604/01.3001.0014.9554","url":null,"abstract":"The night time, based on many world studies, generates an increased risk of serious accidents (with fatalities and serious injuries). This is especially true for accidents with pedestrians. Pedestrian crossings are very sensitive to the influence of the time of day in terms of pedestrian safety, elements of road infrastructure. This is visible on the example of Poland, where numerous accidents at crosswalks are recorded, characterized by high severity at night. Road infra-structure managers take corrective actions to improve this condition. An example of such work is the Road Safety Audit (RSA), initiated in 2016 by the Municipal Roads Management Board in Warsaw. The analyses carried out by the au-thors, among others, in the years 2016 - 2019, included pedestrian crossings without traffic lights located on roads managed by ZDM (Municipal Roads Authority) in twelve districts: Bemowo, Bielany, Mokotów, Ochota, Praga Połud-nie, Praga Północ, Śródmieście, Targówek, Ursynów, Wawer, Włochy, Żoliborz. The assessment was carried out in terms of the correct lighting of these passages, traffic organization, geometry and environmental impact. The main aim of the article is to present a methodology for evaluating the technical condition of road lighting infrastructure on a large scale (e.g. district, city). The article discusses the general and detailed state of pedestrian safety in Poland against the background of research conducted in Warsaw. The procedure of inspection and assessment of the state of lighting of pedestrian crossings is described and selected results are presented. On the basis of a detailed analysis of the results of individual pedestrian crossings, the general condition of the tested crossings was assessed and recommendations were indicated. An attempt was made to assess the influence of pedestrian crossings lighting on the general state of road safety. A critical evaluation of the obtained effects was made. The utilitarian aim of the article is to apply the described methodology in other cities and to use the results of the conducted analyses to plan and implement road investments in the field of modernization of lighting at pedestrian crossings on a large scale.\u0000\u0000","PeriodicalId":53541,"journal":{"name":"Archives of Transport","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47942361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.5604/01.3001.0015.2646
M. Fallah Tafti, R. Roshani
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.
{"title":"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","authors":"M. Fallah Tafti, R. Roshani","doi":"10.5604/01.3001.0015.2646","DOIUrl":"https://doi.org/10.5604/01.3001.0015.2646","url":null,"abstract":"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.\u0000\u0000","PeriodicalId":53541,"journal":{"name":"Archives of Transport","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45303505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.5604/01.3001.0015.0093
Zihao Xie, Wu Zhenfeng, L. Zhu, Wangcai Ding
Different types and quantities of freight cars will affect the marshalling forms of freight trains. In order to investigate the influence of the marshalling forms on the aerodynamic performance of freight trains under crosswind, three types of freight cars such as box cars, gondola cars and tank cars, were selected to marshal with locomotives. This paper used Detached Eddy Simulation method (DES) based on the SST k − ω turbulent model to simulate the aerodynamic performance of the freight train under crosswind. The wind speed, wind angle and train running speed were set as 25m/s, 45° and 100km/h respectively. The influence of different marshalling forms on the aerodynamic performance of the freight train such as aerodynamic drag and lateral force were calculated and compared. The results showed that the marshalling forms have significant effect on the aerodynamic drag and the maximum difference of the aerodynamic drag can reach 20.5%. Furthermore, the variations of the lateral force of the whole train and the locomotive are not apparent. The maximum difference is only 4.3% and 4.1% respectively. However, the changes of marshalling forms have obvious influence on the lateral force of each carriage. The maximum difference of the lateral force of the box car, gondola car and tank car is 17%, 20.1% and 24.1% respectively. The essential reason why the marshalling forms has a significant impact on the aerodynamic performance of the freight train is that there are obvious differences in the volume and shape structure of each railway carriage. The large volume of box cars and the cavity structure of gondola cars make their position a key factor affecting the aerodynamic performance of freight trains. Among the six different marshalling forms selected in this paper, the best marshalling form is: locomotive--gondola car--box car--tank car. Both the aerodynamic drag of the train and the lateral force of the boxcar are the smallest by taking this marshalling form.
{"title":"The effect of different marshalling forms on the aerodynamic performance of the freight train under crosswind","authors":"Zihao Xie, Wu Zhenfeng, L. Zhu, Wangcai Ding","doi":"10.5604/01.3001.0015.0093","DOIUrl":"https://doi.org/10.5604/01.3001.0015.0093","url":null,"abstract":"Different types and quantities of freight cars will affect the marshalling forms of freight trains. In order to investigate the influence of the marshalling forms on the aerodynamic performance of freight trains under crosswind, three types of freight cars such as box cars, gondola cars and tank cars, were selected to marshal with locomotives. This paper used Detached Eddy Simulation method (DES) based on the SST k − ω turbulent model to simulate the aerodynamic performance of the freight train under crosswind. The wind speed, wind angle and train running speed were set as 25m/s, 45° and 100km/h respectively. The influence of different marshalling forms on the aerodynamic performance of the freight train such as aerodynamic drag and lateral force were calculated and compared. The results showed that the marshalling forms have significant effect on the aerodynamic drag and the maximum difference of the aerodynamic drag can reach 20.5%. Furthermore, the variations of the lateral force of the whole train and the locomotive are not apparent. The maximum difference is only 4.3% and 4.1% respectively. However, the changes of marshalling forms have obvious influence on the lateral force of each carriage. The maximum difference of the lateral force of the box car, gondola car and tank car is 17%, 20.1% and 24.1% respectively. The essential reason why the marshalling forms has a significant impact on the aerodynamic performance of the freight train is that there are obvious differences in the volume and shape structure of each railway carriage. The large volume of box cars and the cavity structure of gondola cars make their position a key factor affecting the aerodynamic performance of freight trains. Among the six different marshalling forms selected in this paper, the best marshalling form is: locomotive--gondola car--box car--tank car. Both the aerodynamic drag of the train and the lateral force of the boxcar are the smallest by taking this marshalling form.","PeriodicalId":53541,"journal":{"name":"Archives of Transport","volume":"32 7","pages":"57-71"},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41269275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.5604/01.3001.0015.2390
Fadi Alhomaidat, Tamer Eljufout
Over the last decade, there has been a growing number of individuals using cycling for transport. However, a fraction of workers in the United States of America (USA) are riding bicycles for commuting due to different risk and need factors. Cycling still has serious obstacles to be utilized as alternative transportation. Therefore, there is a need to have a better understanding of the perceived risk/need factors among cyclists. This survey study clarifies the awareness among cyclists of different categories of Risk/Need Factors (RNF) and it contributes to a better understanding of the differences in perceived risks/needs within age groups, genders, and skill levels. An online survey was conducted that included three main categories of Risk/Need Factors (RNF) related to cycling: infrastructure-related, traffic-related, and facility-related. Mean Score Analysis and Ordered Probit Model were used to examine the differences in risk/need perception among cyclists of different ages, genders, and skill levels. According to the study outcomes, older cyclists are influenced more than young cyclists with the infrastructure-related RNF’s. Moreover, gender was not statistically significant when related to perceived RNF. Also, it was found that there are significant differences in the RNF’s among cyclists’ skill levels, infrastructure-related, and facility-related. The study findings emphasize the importance of improv-ing cyclists’ safety and promoting cycling for transportation. Meanwhile, beginner-skilled cyclists are more likely to be influenced by infrastructure-related RNF when compared to other skill levels. The findings of this study give clarifica-tions for potential issues that contribute to a better understanding of the differences in perceived risks/needs among age groups, genders, and skill levels. This reflects among the efforts to promote cycling safety and support cycling for transportation. Therefore, policymakers and city planners should consider the differences in RNF’s in developing cycling infrastructures and traffic management. This allows the urban street system to operate more efficiently, safely, and reliably for all users. Which will enhance the safety awareness of cyclists, reduce the risk factors in the long run, and play a leading role in increasing the number of cyclists.
{"title":"Perception of cycling risks and needs associated with skill level, gender, and age","authors":"Fadi Alhomaidat, Tamer Eljufout","doi":"10.5604/01.3001.0015.2390","DOIUrl":"https://doi.org/10.5604/01.3001.0015.2390","url":null,"abstract":"Over the last decade, there has been a growing number of individuals using cycling for transport. However, a fraction of workers in the United States of America (USA) are riding bicycles for commuting due to different risk and need factors. Cycling still has serious obstacles to be utilized as alternative transportation. Therefore, there is a need to have a better understanding of the perceived risk/need factors among cyclists. This survey study clarifies the awareness among cyclists of different categories of Risk/Need Factors (RNF) and it contributes to a better understanding of the differences in perceived risks/needs within age groups, genders, and skill levels. An online survey was conducted that included three main categories of Risk/Need Factors (RNF) related to cycling: infrastructure-related, traffic-related, and facility-related. Mean Score Analysis and Ordered Probit Model were used to examine the differences in risk/need perception among cyclists of different ages, genders, and skill levels. According to the study outcomes, older cyclists are influenced more than young cyclists with the infrastructure-related RNF’s. Moreover, gender was not statistically significant when related to perceived RNF. Also, it was found that there are significant differences in the RNF’s among cyclists’ skill levels, infrastructure-related, and facility-related. The study findings emphasize the importance of improv-ing cyclists’ safety and promoting cycling for transportation. Meanwhile, beginner-skilled cyclists are more likely to be influenced by infrastructure-related RNF when compared to other skill levels. The findings of this study give clarifica-tions for potential issues that contribute to a better understanding of the differences in perceived risks/needs among age groups, genders, and skill levels. This reflects among the efforts to promote cycling safety and support cycling for transportation. Therefore, policymakers and city planners should consider the differences in RNF’s in developing cycling infrastructures and traffic management. This allows the urban street system to operate more efficiently, safely, and reliably for all users. Which will enhance the safety awareness of cyclists, reduce the risk factors in the long run, and play a leading role in increasing the number of cyclists.\u0000\u0000","PeriodicalId":53541,"journal":{"name":"Archives of Transport","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47406831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-30DOI: 10.5604/01.3001.0015.0466
A. Gill, S. Szrama
A key element of exploitation processes constitutes maintenance operations and tasks. While being conducted in the proper way, they have a crucial effect on achieving the assumed by aircraft designer and operator goals. Properly conducted maintenance operations allow to meet all the technical objects readiness requirements as well as to achieve desired acceptable risk level. Maintenance system effectiveness might be generally a crucial task for company or entity responsible for the maintenance. In this context, particularly relevant become technical object maintenance procedures and tasks developed by their manufacturers. Experience of the article authors quite early shows the need of the mainte-nance programmes modification. Aircraft manufacturers usually are not so eager to develop and implement mainte-nance programme modifications. Presented situation is very much the case in aviation transport. This was the reason why authors of this article decided to prepare and develop this elaboration which might constitute the assistance and supports complex technical objects users in maintenance decision. The main purpose of this article is to present maintenance decisions’ supporting method for the aircraft operators. This article provides guidelines which include a description of risk in the context of aviation maintenance and introduction of some methodologies, tools and criteria that support identification, analysis and evaluation of risk. Authors included idea, how the aircraft preventive maintenance could be used to mitigate aircraft failure risk during flight operations. It also shows how to adopt and develop effective maintenance program using tools for adequate risk analysis, optimal interval assignments, and selection of the most effective maintenance task. Authors presented methodology and de-scribed steps of the logic diagram analysis for the aircraft systems and their components, in order to manage and adopt aircraft maintenance program to fulfil aircraft airworthiness requirements and operational availability. The whole methodology was described on the basis of the F 16 aircraft maintenance system and with reference to the maintenance data. This article might also constitute an introduction to the aircraft maintenance programme development method.
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Pub Date : 2021-06-30DOI: 10.5604/01.3001.0014.8798
J. Kisilowski, J. Zalewski
In this paper some selected results related to motor vehicle dynamics have been presented basing on the computer simulations of a sports two-seater performing a power-off straight line maneuver with different road conditions and the lack of a straight-line motion control having been included. All simulations have been performed in the MSC Ad-ams/Car environment and the adopted maneuver was performed at the instant speed of 100km∙h-1. The selected phe-nomena have therefore been observed along the road long enough to relate them to different aspects of vehicle dynam-ics and the road traffic safety research. The adopted vehicle’s model moved along the flat and the randomly uneven road with the almost similar and the almost different profiles for the left and the right wheels. Additionally, two values of the coefficient determining the maximum amplitude of road irregularities have been selected, i.e., 0.3 for the lower and 0.9 for the higher irregularities. This meant that the road conditions have been considered as one of the main factors possibly affecting disturbances of the motor vehicle’s motion. Such research seems valuable from the point of view of the road safety and the vehicles’ maintenance. A power-off straight maneuver is not very often performed during the normal road traffic and might seem useless. However, in this case it seemed essential to test the response of a vehicle’s model to such factors as, e.g., the uneven loading, suspension characteristics, etc. This in turn might prove valuable when considering, e.g., the additional con-centration of a driver to overcome the external disturbances acting on a moving vehicle. The presented research is the second part of the paper (Kisilowski, 2019) where the power-off maneuver was considered but with the straightforward motion control. Here, the straight-line control has been switched off to examine an untypical situation where, for example a driver loses consciousness, and the vehicle moves freely along the road.
{"title":"An example of a power-off maneuver of a vehicle without a straight line motion control","authors":"J. Kisilowski, J. Zalewski","doi":"10.5604/01.3001.0014.8798","DOIUrl":"https://doi.org/10.5604/01.3001.0014.8798","url":null,"abstract":"In this paper some selected results related to motor vehicle dynamics have been presented basing on the computer simulations of a sports two-seater performing a power-off straight line maneuver with different road conditions and the lack of a straight-line motion control having been included. All simulations have been performed in the MSC Ad-ams/Car environment and the adopted maneuver was performed at the instant speed of 100km∙h-1. The selected phe-nomena have therefore been observed along the road long enough to relate them to different aspects of vehicle dynam-ics and the road traffic safety research. The adopted vehicle’s model moved along the flat and the randomly uneven road with the almost similar and the almost different profiles for the left and the right wheels. Additionally, two values of the coefficient determining the maximum amplitude of road irregularities have been selected, i.e., 0.3 for the lower and 0.9 for the higher irregularities. This meant that the road conditions have been considered as one of the main factors possibly affecting disturbances of the motor vehicle’s motion. Such research seems valuable from the point of view of the road safety and the vehicles’ maintenance.\u0000A power-off straight maneuver is not very often performed during the normal road traffic and might seem useless. However, in this case it seemed essential to test the response of a vehicle’s model to such factors as, e.g., the uneven loading, suspension characteristics, etc. This in turn might prove valuable when considering, e.g., the additional con-centration of a driver to overcome the external disturbances acting on a moving vehicle. The presented research is the second part of the paper (Kisilowski, 2019) where the power-off maneuver was considered but with the straightforward motion control. Here, the straight-line control has been switched off to examine an untypical situation where, for example a driver loses consciousness, and the vehicle moves freely along the road.\u0000\u0000","PeriodicalId":53541,"journal":{"name":"Archives of Transport","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45053399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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