Pub Date : 2021-07-19DOI: 10.1080/19439962.2021.1949414
E. Adanu, W. Agyemang, Riffat Islam, Steven L. Jones
Abstract This paper identifies factors that influence the severity of interstate crash outcomes and how they vary depending on the location and manner of collision. Four separate injury severity models were developed to explore the differences and similarities in crash factors between single-and multi-vehicle crashes that occurred in rural and urban areas of the state. Random parameters multinomial logit with heterogeneity in means and variances modeling approach was used to account for unobserved heterogeneity in the crash data. The model estimation results show that some driver behavioral factors such as speeding, aggressive driving, failure to use seatbelt, and driving without a valid license were found to significantly contribute to some form of injury outcome. The influence of roadway features such as type of opposing lane separation, collision type, temporal and lighting conditions on crash outcomes were also explored. Some differences and similarities in the associations between these factors and crash injury severity based on the manner and location of crash were unraveled. These findings are expected to guide the implementation of crash countermeasures on interstates. The findings of this study further support the evidence for the analysis of subsets of crash data to unravel underlying complex relationships within factors that influence crash injury severity.
{"title":"A comprehensive analysis of factors that influence interstate highway crash severity in Alabama","authors":"E. Adanu, W. Agyemang, Riffat Islam, Steven L. Jones","doi":"10.1080/19439962.2021.1949414","DOIUrl":"https://doi.org/10.1080/19439962.2021.1949414","url":null,"abstract":"Abstract This paper identifies factors that influence the severity of interstate crash outcomes and how they vary depending on the location and manner of collision. Four separate injury severity models were developed to explore the differences and similarities in crash factors between single-and multi-vehicle crashes that occurred in rural and urban areas of the state. Random parameters multinomial logit with heterogeneity in means and variances modeling approach was used to account for unobserved heterogeneity in the crash data. The model estimation results show that some driver behavioral factors such as speeding, aggressive driving, failure to use seatbelt, and driving without a valid license were found to significantly contribute to some form of injury outcome. The influence of roadway features such as type of opposing lane separation, collision type, temporal and lighting conditions on crash outcomes were also explored. Some differences and similarities in the associations between these factors and crash injury severity based on the manner and location of crash were unraveled. These findings are expected to guide the implementation of crash countermeasures on interstates. The findings of this study further support the evidence for the analysis of subsets of crash data to unravel underlying complex relationships within factors that influence crash injury severity.","PeriodicalId":46672,"journal":{"name":"Journal of Transportation Safety & Security","volume":"84 1","pages":"1552 - 1576"},"PeriodicalIF":2.6,"publicationDate":"2021-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85933621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-15DOI: 10.1080/19439962.2021.1949413
N. Nadimi, Esmaeil Sheikh Hosseini Lori
Abstract Various analytic methods have been proposed to determine sections with the highest crash risk. Each method has unique specifications and tries to model the crash risk from a different viewpoint. The main objective of this article is to benefit the strengths of three methods that rely on accident data, road safety inspection, and traffic conflict technique to determine black spots for two-lane highways simultaneously. Fuzzy inference system (FIS) is considered as the method to combine the results of these methods and report one number (R MI) as the crash risk for each section. For comparative evaluations, a case study with 20 sections for two consecutive periods was considered in the roads of southeast of Iran. We have tried to select sections with various conditions from crash data, road condition, and surrogate safety measures viewpoint. First, the black spots are determined with the help of previous criteria such as crash frequency (CF), crash rate (CR), empirical Bayes (EB), and equivalent property damage only (EPDO). Then the black spots are specified by the new proposed criteria (R MI). Three tests are applied to compare the efficiency of these five methods. The results indicate that the proposed method is a powerful tool to identify black spots. R MI considers the frequency and severity of observed crashes and at the same time frequency and severity of predicted crashes based on road deficiencies and near crashes. Therefore, it has a more realistic attitude in black spot identification.
{"title":"Applying different analytic methods to determine black spots in two-lane highways","authors":"N. Nadimi, Esmaeil Sheikh Hosseini Lori","doi":"10.1080/19439962.2021.1949413","DOIUrl":"https://doi.org/10.1080/19439962.2021.1949413","url":null,"abstract":"Abstract Various analytic methods have been proposed to determine sections with the highest crash risk. Each method has unique specifications and tries to model the crash risk from a different viewpoint. The main objective of this article is to benefit the strengths of three methods that rely on accident data, road safety inspection, and traffic conflict technique to determine black spots for two-lane highways simultaneously. Fuzzy inference system (FIS) is considered as the method to combine the results of these methods and report one number (R MI) as the crash risk for each section. For comparative evaluations, a case study with 20 sections for two consecutive periods was considered in the roads of southeast of Iran. We have tried to select sections with various conditions from crash data, road condition, and surrogate safety measures viewpoint. First, the black spots are determined with the help of previous criteria such as crash frequency (CF), crash rate (CR), empirical Bayes (EB), and equivalent property damage only (EPDO). Then the black spots are specified by the new proposed criteria (R MI). Three tests are applied to compare the efficiency of these five methods. The results indicate that the proposed method is a powerful tool to identify black spots. R MI considers the frequency and severity of observed crashes and at the same time frequency and severity of predicted crashes based on road deficiencies and near crashes. Therefore, it has a more realistic attitude in black spot identification.","PeriodicalId":46672,"journal":{"name":"Journal of Transportation Safety & Security","volume":"98 1","pages":"1395 - 1418"},"PeriodicalIF":2.6,"publicationDate":"2021-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80760068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-12DOI: 10.1080/19439962.2021.1949415
Xueqin Long, Meng Zhou, Huan Zhao, Ya’nan Song
Abstract During the signal-transition period for the signalized intersection, pedestrians will face a dilemma of whether to cross or wait. The study establishes a decision model of pedestrian-crossing based on risk-cost and time-utility during flashing green-countdown signal. First, the calculation methods of potential and direct risk in each direction of the intersection are proposed according to the traffic operation status. Then, analyze the relationship among the arrival time, remaining duration of flashing green signal and the actual crossing behavior, pedestrians are divided into adventurous, ordinary and conservative types respectively. Finally, introducing the time utility function, crossing decision models of three types pedestrians are established respectively based on comparing the risk cost and time utility. Take two signalized intersections as examples, parameters of decision models are calibrated through field investigation. Three types of models’ accuracy rates for the adventurous, ordinary and conservative pedestrians are 80%, 90% and 60% respectively, which denotes that the models can accurately predict the decision behavior of adventurous and ordinary pedestrians. Additionally, pedestrians are less sensitive to risk and more sensitive to time when they are faced with urgent time.
{"title":"Pedestrian crossing decision during flashing green-countdown signal for urban signalized intersection","authors":"Xueqin Long, Meng Zhou, Huan Zhao, Ya’nan Song","doi":"10.1080/19439962.2021.1949415","DOIUrl":"https://doi.org/10.1080/19439962.2021.1949415","url":null,"abstract":"Abstract During the signal-transition period for the signalized intersection, pedestrians will face a dilemma of whether to cross or wait. The study establishes a decision model of pedestrian-crossing based on risk-cost and time-utility during flashing green-countdown signal. First, the calculation methods of potential and direct risk in each direction of the intersection are proposed according to the traffic operation status. Then, analyze the relationship among the arrival time, remaining duration of flashing green signal and the actual crossing behavior, pedestrians are divided into adventurous, ordinary and conservative types respectively. Finally, introducing the time utility function, crossing decision models of three types pedestrians are established respectively based on comparing the risk cost and time utility. Take two signalized intersections as examples, parameters of decision models are calibrated through field investigation. Three types of models’ accuracy rates for the adventurous, ordinary and conservative pedestrians are 80%, 90% and 60% respectively, which denotes that the models can accurately predict the decision behavior of adventurous and ordinary pedestrians. Additionally, pedestrians are less sensitive to risk and more sensitive to time when they are faced with urgent time.","PeriodicalId":46672,"journal":{"name":"Journal of Transportation Safety & Security","volume":"100 1","pages":"1577 - 1597"},"PeriodicalIF":2.6,"publicationDate":"2021-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79307968","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-29DOI: 10.1080/19439962.2021.1938323
Peijie Wu, Xianghai Meng, Li Song
Abstract The problem of urban crashes brings huge challenges and threats to local police and governments, especially in many cities in developing countries such as China. To reduce the frequency and severity of urban crashes, the local government in China has gradually taken interest in conducting detailed actions of traffic safety improvement at the microzone-level. Therefore, the primary goal of this study is to try a new method in spatiotemporal data mining techniques, the space-time cube method, to find high-risk crash spots at the spatiotemporal level and to obtain their spatiotemporal evolution patterns. The cumulative frequency curve method was performed to identify high-risk crash spots, and the contributory factors of forming these spots were analyzed by the latent class analysis method. The results showed that: (1) key parameters’ selection is crucial in the space-time cube construction; (2) the exit ramp gore point in interchanges, intersections, and entrances of neighborhoods were prone to have many high-risk crash spots at the spatiotemporal scale; and (3) locations with consecutive, persistent, and sporadic hotspots patterns need different risk monitoring strategies and traffic safety improvement. The feasibility and advantages of the space-time cube method in hotspots identification at the microzone-level were confirmed.
{"title":"Identification and spatiotemporal evolution analysis of high-risk crash spots in urban roads at the microzone-level: Using the space-time cube method","authors":"Peijie Wu, Xianghai Meng, Li Song","doi":"10.1080/19439962.2021.1938323","DOIUrl":"https://doi.org/10.1080/19439962.2021.1938323","url":null,"abstract":"Abstract The problem of urban crashes brings huge challenges and threats to local police and governments, especially in many cities in developing countries such as China. To reduce the frequency and severity of urban crashes, the local government in China has gradually taken interest in conducting detailed actions of traffic safety improvement at the microzone-level. Therefore, the primary goal of this study is to try a new method in spatiotemporal data mining techniques, the space-time cube method, to find high-risk crash spots at the spatiotemporal level and to obtain their spatiotemporal evolution patterns. The cumulative frequency curve method was performed to identify high-risk crash spots, and the contributory factors of forming these spots were analyzed by the latent class analysis method. The results showed that: (1) key parameters’ selection is crucial in the space-time cube construction; (2) the exit ramp gore point in interchanges, intersections, and entrances of neighborhoods were prone to have many high-risk crash spots at the spatiotemporal scale; and (3) locations with consecutive, persistent, and sporadic hotspots patterns need different risk monitoring strategies and traffic safety improvement. The feasibility and advantages of the space-time cube method in hotspots identification at the microzone-level were confirmed.","PeriodicalId":46672,"journal":{"name":"Journal of Transportation Safety & Security","volume":"11 1","pages":"1510 - 1530"},"PeriodicalIF":2.6,"publicationDate":"2021-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89398847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract A bus-involved crash unavoidably affects many passengers, causing severe consequences. Nonetheless, few studies have been comprehensively conducted to analyze the bus-crash severity. Accordingly, using the data of the bus crashes that have occurred in the UK in 2017–2019, this study constructs an extended hierarchical ordered probit model with heteroscedasticity (HHOPIT) to investigate the factors influencing bus-crash severity levels. Using AIC and BIC indicators, we confirm that considering the impact of variable heterogeneity on the threshold and error term is essential for interpreting bus-crash severity. Particularly, the frontal-impact-crash, wet-road, and moderate-speed-limit variables produce heteroscedasticity and significantly affect the crash severity level. Additionally, overturned-crash, multi-vehicle-crash, and morning-crash variables induce threshold variability. Based on the marginal effect of variables, it is confirmed that road-section, frontal-impact-crash, wet-road, junction-exit, and main-way variables increase the likelihood of severe injuries. Furthermore, the probability of slight injuries as consequences, increases with the influence of lower-speed-limit, roundabout, urban-crash, parking-crash, and moderate-speed-limit variables. This study additionally determines the factors that have inconsistent effects on the consequence of bus and passenger-car crashes. To improve the safety of bus services, the authorities must carefully consider the heterogeneity and specificities of the factors affecting bus-crash severity and appropriately formulate targeted policies.
{"title":"Investigation of factors contributing to bus-crash severity based on extended hierarchical ordered probit model with heteroscedasticity","authors":"Jinxing Shen, Hongyan Gu, Xuejun Feng, Miao Yu, Changjiang Zheng","doi":"10.1080/19439962.2021.1941460","DOIUrl":"https://doi.org/10.1080/19439962.2021.1941460","url":null,"abstract":"Abstract A bus-involved crash unavoidably affects many passengers, causing severe consequences. Nonetheless, few studies have been comprehensively conducted to analyze the bus-crash severity. Accordingly, using the data of the bus crashes that have occurred in the UK in 2017–2019, this study constructs an extended hierarchical ordered probit model with heteroscedasticity (HHOPIT) to investigate the factors influencing bus-crash severity levels. Using AIC and BIC indicators, we confirm that considering the impact of variable heterogeneity on the threshold and error term is essential for interpreting bus-crash severity. Particularly, the frontal-impact-crash, wet-road, and moderate-speed-limit variables produce heteroscedasticity and significantly affect the crash severity level. Additionally, overturned-crash, multi-vehicle-crash, and morning-crash variables induce threshold variability. Based on the marginal effect of variables, it is confirmed that road-section, frontal-impact-crash, wet-road, junction-exit, and main-way variables increase the likelihood of severe injuries. Furthermore, the probability of slight injuries as consequences, increases with the influence of lower-speed-limit, roundabout, urban-crash, parking-crash, and moderate-speed-limit variables. This study additionally determines the factors that have inconsistent effects on the consequence of bus and passenger-car crashes. To improve the safety of bus services, the authorities must carefully consider the heterogeneity and specificities of the factors affecting bus-crash severity and appropriately formulate targeted policies.","PeriodicalId":46672,"journal":{"name":"Journal of Transportation Safety & Security","volume":"76 1","pages":"1531 - 1551"},"PeriodicalIF":2.6,"publicationDate":"2021-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90399301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-15DOI: 10.1080/19439962.2021.1923101
Bo Qiu, W. Fan
Abstract Pedestrian injury has become a national traffic-safety concern as the share of pedestrian fatality continues to increase in the last decade. Pedestrian injury severities are influenced by many factors that include driver, pedestrian, vehicle, roadway, temporal, and environmental characteristics. Results indicate that some of the factors affecting pedestrian injury severity at intersection and non-intersection locations are statistically different and using the same model to perform the estimate at both locations may result in biased results. However, few studies have been conducted to explore different contributing factors at such locations. Mixed logit models are developed to independently identify the contributing factors to pedestrian injury severity resulting from crashes at intersections and non-intersections. The estimation shows factors such as male driver, alcohol, pedestrian above 65, truck, and higher speed limit significantly increase the probability of pedestrian serious injury severities in both locations. However, the impacts tend to be more severe at intersections. Urban and wet road surfaces decrease the likelihood of suffering fatal injury at intersections. Furthermore, crash time only has impacts at intersections, while traffic control, severe weather, and day-of-week only have impacts at non-intersections. The results provide insights on developing more effective countermeasures to promote pedestrian safety.
{"title":"Mixed logit models for examining pedestrian injury severities at intersection and non-intersection locations","authors":"Bo Qiu, W. Fan","doi":"10.1080/19439962.2021.1923101","DOIUrl":"https://doi.org/10.1080/19439962.2021.1923101","url":null,"abstract":"Abstract Pedestrian injury has become a national traffic-safety concern as the share of pedestrian fatality continues to increase in the last decade. Pedestrian injury severities are influenced by many factors that include driver, pedestrian, vehicle, roadway, temporal, and environmental characteristics. Results indicate that some of the factors affecting pedestrian injury severity at intersection and non-intersection locations are statistically different and using the same model to perform the estimate at both locations may result in biased results. However, few studies have been conducted to explore different contributing factors at such locations. Mixed logit models are developed to independently identify the contributing factors to pedestrian injury severity resulting from crashes at intersections and non-intersections. The estimation shows factors such as male driver, alcohol, pedestrian above 65, truck, and higher speed limit significantly increase the probability of pedestrian serious injury severities in both locations. However, the impacts tend to be more severe at intersections. Urban and wet road surfaces decrease the likelihood of suffering fatal injury at intersections. Furthermore, crash time only has impacts at intersections, while traffic control, severe weather, and day-of-week only have impacts at non-intersections. The results provide insights on developing more effective countermeasures to promote pedestrian safety.","PeriodicalId":46672,"journal":{"name":"Journal of Transportation Safety & Security","volume":"51 1","pages":"1333 - 1357"},"PeriodicalIF":2.6,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84944210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-15DOI: 10.1080/19439962.2021.1933284
Zongni Gu, Ilir Bejleri, Binbin Peng
Abstract While traffic crash duration on freeways and its association with crash characteristics have been studied extensively, limited research exists regarding the characteristics of crash duration in urban arterials and collectors and their influential factors. To better understand this relationship, this study examines the effects of crash characteristics, roadway features, temporal variables, and other variables on crash duration. To this aim, the study applies the accelerated failure time (AFT) hazards-based model on principal arterials, minor arterials, major collectors, and minor collectors using Miami-Dade County in Florida (USA) as the study area. Results show that the average crash durations in minor arterials are longer than in all other road types. When it comes to the total time duration of crashes, different types of roads have different characteristics. Specifically, when the road crashes were cleared up within 76 min, principal arterials take a shorter time than the other three types of roads to clean the scene. On the contrary, when the crash endured more than 76 min for cleanups, the crash durations in collectors were shorter than in arterials. Consistent with findings from previous studies in freeways, the results show that severe crashes are associated with increased crash durations in most urban arterials and collectors. Moreover, the impact of crash characteristics on crash duration varies across road types. A greater number of vehicles and passengers involved in crashes is associated with longer durations in all but minor collectors. With regard to roadway features, the effects on crash durations vary by road type. In addition, early morning was more likely to be associated with longer crash durations than other periods, specifically strongly affecting the crash durations in minor collectors. These findings indicate that the effects of factors on crash durations vary depending on road type and may require different actions for their effective resolution.
{"title":"Exploring characteristics and influencing factors of crash duration on urban arterials and collectors","authors":"Zongni Gu, Ilir Bejleri, Binbin Peng","doi":"10.1080/19439962.2021.1933284","DOIUrl":"https://doi.org/10.1080/19439962.2021.1933284","url":null,"abstract":"Abstract While traffic crash duration on freeways and its association with crash characteristics have been studied extensively, limited research exists regarding the characteristics of crash duration in urban arterials and collectors and their influential factors. To better understand this relationship, this study examines the effects of crash characteristics, roadway features, temporal variables, and other variables on crash duration. To this aim, the study applies the accelerated failure time (AFT) hazards-based model on principal arterials, minor arterials, major collectors, and minor collectors using Miami-Dade County in Florida (USA) as the study area. Results show that the average crash durations in minor arterials are longer than in all other road types. When it comes to the total time duration of crashes, different types of roads have different characteristics. Specifically, when the road crashes were cleared up within 76 min, principal arterials take a shorter time than the other three types of roads to clean the scene. On the contrary, when the crash endured more than 76 min for cleanups, the crash durations in collectors were shorter than in arterials. Consistent with findings from previous studies in freeways, the results show that severe crashes are associated with increased crash durations in most urban arterials and collectors. Moreover, the impact of crash characteristics on crash duration varies across road types. A greater number of vehicles and passengers involved in crashes is associated with longer durations in all but minor collectors. With regard to roadway features, the effects on crash durations vary by road type. In addition, early morning was more likely to be associated with longer crash durations than other periods, specifically strongly affecting the crash durations in minor collectors. These findings indicate that the effects of factors on crash durations vary depending on road type and may require different actions for their effective resolution.","PeriodicalId":46672,"journal":{"name":"Journal of Transportation Safety & Security","volume":"32 1","pages":"1470 - 1489"},"PeriodicalIF":2.6,"publicationDate":"2021-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91388008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-02DOI: 10.1080/19439962.2021.1933285
Ghalia Gamaleldin, H. Al-Deek, Adrian Sandt, John McCombs
Abstract Safety performance functions (SPFs) are used to predict intersection crashes. Unlike previous studies, which only used the three categories outlined in the Highway Safety Manual (HSM) to develop SPFs, this research developed SPFs based on a new context classification system developed by the Florida Department of Transportation (FDOT) which categorizes intersections into eight context categories. Two types of comparisons were used to evaluate the benefits of context-specific SPFs for the C3R-Suburban Residential and C4-Urban General context categories. First, individual intersection group SPFs were developed for unsignalized and signalized 3-leg and 4-leg intersection groups within each category. These individual SPFs were then compared to full category SPFs using data from all four intersection groups. The individual SPFs typically had lower performance measure values and more accurate crash predictions than the full SPFs while containing additional variables. For example, FDOT District 7 and major median were significant in several individual C3R SPFs but not in the full SPF. Next, comparisons were made between context-specific SPFs and HSM SPFs for two intersection groups (C3R signalized 4-leg and C4 unsignalized 3-leg). The context-specific SPFs outperformed the HSM SPFs in predicting multi-vehicle crashes, demonstrating the improved benefits that agencies can gain by developing context-specific SPFs.
{"title":"Evaluating the benefits of using a context classification system to develop intersection safety performance functions","authors":"Ghalia Gamaleldin, H. Al-Deek, Adrian Sandt, John McCombs","doi":"10.1080/19439962.2021.1933285","DOIUrl":"https://doi.org/10.1080/19439962.2021.1933285","url":null,"abstract":"Abstract Safety performance functions (SPFs) are used to predict intersection crashes. Unlike previous studies, which only used the three categories outlined in the Highway Safety Manual (HSM) to develop SPFs, this research developed SPFs based on a new context classification system developed by the Florida Department of Transportation (FDOT) which categorizes intersections into eight context categories. Two types of comparisons were used to evaluate the benefits of context-specific SPFs for the C3R-Suburban Residential and C4-Urban General context categories. First, individual intersection group SPFs were developed for unsignalized and signalized 3-leg and 4-leg intersection groups within each category. These individual SPFs were then compared to full category SPFs using data from all four intersection groups. The individual SPFs typically had lower performance measure values and more accurate crash predictions than the full SPFs while containing additional variables. For example, FDOT District 7 and major median were significant in several individual C3R SPFs but not in the full SPF. Next, comparisons were made between context-specific SPFs and HSM SPFs for two intersection groups (C3R signalized 4-leg and C4 unsignalized 3-leg). The context-specific SPFs outperformed the HSM SPFs in predicting multi-vehicle crashes, demonstrating the improved benefits that agencies can gain by developing context-specific SPFs.","PeriodicalId":46672,"journal":{"name":"Journal of Transportation Safety & Security","volume":"18 1","pages":"1490 - 1509"},"PeriodicalIF":2.6,"publicationDate":"2021-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74351873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-06-02DOI: 10.1080/19439962.2021.1928353
Yao Yu, Guorong Li, Jinxian Weng
Abstract The underreporting issue on shipping accident data has plagued the researchers focused on maritime safety analysis for many years. For improving the quality of shipping accident records, this study proposes a novel methodology comprising three steps to complement the underreported maritime accident records. The first step is to investigate the underreporting rates under various conditions through questionnaire survey. Based on the survey results, the second step is to build a Cluster-Specific Random Effects (CSRE) model to estimate the underreporting rates under various scenarios. Then, the third step is to replicate the underreported accident records using the Monte Carlo simulation technique. Model results show that the occurrence probability of missing accident records involving liquid cargo ships is lower than other ship categories while fishing ships are more likely to have a higher underreporting rate. Non-serious accidents are more likely to be underreported than serious accidents. The case study confirms the effectiveness of the proposed three-step method for complementing the maritime accident databases suffering underreporting problems.
摘要多年来，船舶事故数据少报问题一直困扰着从事海上安全分析的研究人员。为了提高船舶事故记录的质量，本研究提出了一种新的方法，包括三个步骤来补充少报的海上事故记录。第一步是通过问卷调查的方式调查不同情况下的漏报率。基于调查结果，第二步是建立集群特定随机效应(Cluster-Specific Random Effects, CSRE)模型，估算不同情景下的漏报率。然后，第三步是使用蒙特卡罗模拟技术复制少报的事故记录。模型结果表明，液货船漏报事故记录的概率低于其他船舶类别，而渔船漏报的概率更高。非严重事故比严重事故更容易被漏报。案例研究证实了拟议的三步法在补充存在漏报问题的海上事故数据库方面的有效性。
{"title":"A three-step methodology to complement underreporting maritime accident records","authors":"Yao Yu, Guorong Li, Jinxian Weng","doi":"10.1080/19439962.2021.1928353","DOIUrl":"https://doi.org/10.1080/19439962.2021.1928353","url":null,"abstract":"Abstract The underreporting issue on shipping accident data has plagued the researchers focused on maritime safety analysis for many years. For improving the quality of shipping accident records, this study proposes a novel methodology comprising three steps to complement the underreported maritime accident records. The first step is to investigate the underreporting rates under various conditions through questionnaire survey. Based on the survey results, the second step is to build a Cluster-Specific Random Effects (CSRE) model to estimate the underreporting rates under various scenarios. Then, the third step is to replicate the underreported accident records using the Monte Carlo simulation technique. Model results show that the occurrence probability of missing accident records involving liquid cargo ships is lower than other ship categories while fishing ships are more likely to have a higher underreporting rate. Non-serious accidents are more likely to be underreported than serious accidents. The case study confirms the effectiveness of the proposed three-step method for complementing the maritime accident databases suffering underreporting problems.","PeriodicalId":46672,"journal":{"name":"Journal of Transportation Safety & Security","volume":"37 1","pages":"1451 - 1469"},"PeriodicalIF":2.6,"publicationDate":"2021-06-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81502526","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-05-26DOI: 10.1080/19439962.2021.1919261
Narayana Raju, S. Arkatkar, S. Easa, G. Joshi
Abstract This paper proposes a novel approach for examining rear-end collisions between successive vehicles in a traffic stream. In this approach, a new safety measure of the follower driver's attentiveness is proposed, referred to herein as instantaneous heeding time (IHT), reflecting the subject follower's heeding nature concerning its leader. A safety framework that integrates the IHT with the distance gap and the instantaneous follower's speed is presented. The applicability of the framework is demonstrated using an Indian-traffic trajectory database (developed in this study) and the homogeneous traffic database of the next generation simulation (NGSIM) project developed in the United States (U.S.). Five study sections in India and two study sections in the U.S. are analyzed for three traffic-flow levels. For Indian traffic, the results show that motorized two-wheelers (MTW) have degraded road safety due to the unrestrained lateral crisscross movements. Due to the presence of MTW, the Indian-traffic stream operates in a disorderly fashion, thereby increasing the probability of rear-end collisions with other vehicle classes. Further, the importance of implementing cautioning measures for drivers that reduce the probability of collisions is demonstrated. Besides, the NGSIM application results confirmed the proposed framework's applicability to both Indian and homogeneous traffic conditions. In practice, the proposed framework can be used in real-time to monitor the driver's aggressive instincts.
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