Pub Date : 2024-07-27DOI: 10.1177/03611981241258985
Swastik Khadka, P. Wang, Pengfei (Taylor) Li, Stephen P. Mattingly
In this paper, we present a digital twin approach to the enhancement of traffic signal performance monitoring and congestion identification using automated traffic signal performance measure (ATSPM) systems. The objective of this effort is to use the high-fidelity microscopic simulation engine to generate simulated traffic signal events and connected vehicle data and allow the ATSPM systems to generate various traffic signal measures of effectiveness (MOEs) for a forensic traffic signal evaluation. Real-world ATSPM systems are driven by the traffic signal logs generated during operations. Therefore, they are primarily applied to traffic signal operations in the field. However, traffic signal design at present still follows the traditional method based on averaged delays, stops, and so forth, while more and more agencies have begun to evaluate the implemented traffic signal systems’ performance using the novel ATSPM MOEs. The proposed ATSPMs-in-the-loop simulation system fills this gap by using the ATSPM systems to evaluate the proposed traffic signal timings at the design stage. The benefits of this system include providing full-spectrum decision support for traffic signal management from design to operation and facilitating agencies to develop new insights on identifying traffic signal problems using the ATSPM MOEs. Another feature of the ATSPMs-in-the-loop simulation system is that it can use the emerging connected vehicle data set to generate new traffic signal MOEs. In the case study, we demonstrate how to use the proposed system to identify the potential issues of detector layouts and bottlenecks. Additional features of this ATSPM digital twin include allowing external components to interact with this platform via standard protocols in traffic control systems and connected vehicles to serve more purposes.
{"title":"Automated Traffic Signal Performance Measures (ATSPMs) in the Loop Simulation: A Digital Twin Approach","authors":"Swastik Khadka, P. Wang, Pengfei (Taylor) Li, Stephen P. Mattingly","doi":"10.1177/03611981241258985","DOIUrl":"https://doi.org/10.1177/03611981241258985","url":null,"abstract":"In this paper, we present a digital twin approach to the enhancement of traffic signal performance monitoring and congestion identification using automated traffic signal performance measure (ATSPM) systems. The objective of this effort is to use the high-fidelity microscopic simulation engine to generate simulated traffic signal events and connected vehicle data and allow the ATSPM systems to generate various traffic signal measures of effectiveness (MOEs) for a forensic traffic signal evaluation. Real-world ATSPM systems are driven by the traffic signal logs generated during operations. Therefore, they are primarily applied to traffic signal operations in the field. However, traffic signal design at present still follows the traditional method based on averaged delays, stops, and so forth, while more and more agencies have begun to evaluate the implemented traffic signal systems’ performance using the novel ATSPM MOEs. The proposed ATSPMs-in-the-loop simulation system fills this gap by using the ATSPM systems to evaluate the proposed traffic signal timings at the design stage. The benefits of this system include providing full-spectrum decision support for traffic signal management from design to operation and facilitating agencies to develop new insights on identifying traffic signal problems using the ATSPM MOEs. Another feature of the ATSPMs-in-the-loop simulation system is that it can use the emerging connected vehicle data set to generate new traffic signal MOEs. In the case study, we demonstrate how to use the proposed system to identify the potential issues of detector layouts and bottlenecks. Additional features of this ATSPM digital twin include allowing external components to interact with this platform via standard protocols in traffic control systems and connected vehicles to serve more purposes.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798602","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 : 2024-07-27DOI: 10.1177/03611981241255597
Yunsheng Zhu, Yang Yuan, Kaifeng Wang, Yang Liu, Lin Xu
For hot recycled asphalt mixture with high content of recycled asphalt pavement (RAP) material, the road performance of the recycled asphalt pavement may be degraded if the aggregate particles of RAP are unevenly dispersed. In this study, recycled asphalt mixture with a RAP content of 50% was used to investigate the uniformity of RAP aggregate. On this basis, the road performance of recycled asphalt mixtures with different RAP dispersion uniformity was analyzed. Firstly, the Marshall test specimens of hot recycled asphalt mixture were prepared and saw-cut, and the microstructure of each cross-section was extracted using digital image processing. Then, based on the distribution characteristics of RAP aggregate inside the mixture, a uniformity index was proposed using the distribution eigenvalue method. Finally, the road performance test was conducted on the recycled asphalt mixture with different RAP dispersion uniformity. The results demonstrate that the homogeneity can be accurately and quantitatively evaluated by a uniformity index based on the area ratio of the RAP aggregate in each cross-section. Higher RAP heating temperature and mixing time result in improved uniformity of RAP aggregates. Meanwhile, the gray correlation analysis revealed a good correlation between the proposed uniformity index and the moisture susceptibility of the recycled asphalt mixture. In short, the quantitative uniformity evaluation index of RAP aggregate presented in this study reflects the homogeneity of hot recycled asphalt mixture, which is helpful for controlling the quality of recycled asphalt pavement.
{"title":"Research on the Performance of Hot Recycled Asphalt Mixture Based on Recycled Asphalt Pavement Dispersion Uniformity","authors":"Yunsheng Zhu, Yang Yuan, Kaifeng Wang, Yang Liu, Lin Xu","doi":"10.1177/03611981241255597","DOIUrl":"https://doi.org/10.1177/03611981241255597","url":null,"abstract":"For hot recycled asphalt mixture with high content of recycled asphalt pavement (RAP) material, the road performance of the recycled asphalt pavement may be degraded if the aggregate particles of RAP are unevenly dispersed. In this study, recycled asphalt mixture with a RAP content of 50% was used to investigate the uniformity of RAP aggregate. On this basis, the road performance of recycled asphalt mixtures with different RAP dispersion uniformity was analyzed. Firstly, the Marshall test specimens of hot recycled asphalt mixture were prepared and saw-cut, and the microstructure of each cross-section was extracted using digital image processing. Then, based on the distribution characteristics of RAP aggregate inside the mixture, a uniformity index was proposed using the distribution eigenvalue method. Finally, the road performance test was conducted on the recycled asphalt mixture with different RAP dispersion uniformity. The results demonstrate that the homogeneity can be accurately and quantitatively evaluated by a uniformity index based on the area ratio of the RAP aggregate in each cross-section. Higher RAP heating temperature and mixing time result in improved uniformity of RAP aggregates. Meanwhile, the gray correlation analysis revealed a good correlation between the proposed uniformity index and the moisture susceptibility of the recycled asphalt mixture. In short, the quantitative uniformity evaluation index of RAP aggregate presented in this study reflects the homogeneity of hot recycled asphalt mixture, which is helpful for controlling the quality of recycled asphalt pavement.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141797396","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 : 2024-07-27DOI: 10.1177/03611981241260705
Nabil Suleiman, Anjo Mate, D. Gedafa, Bruce Dockter
There is a need to develop a new mix design criterion for North Dakota especially for medium- and low-volume traffic pavements, where the durability performance of the hot-mix asphalt (HMA) is of the most importance. High Ndesign numbers tend to lower the asphalt binder, thus lowering the durability of the asphalt mix. In contrast, if Ndesign is reduced, it tends to increase the asphalt binder, thus improving the durability of the asphalt mix. The main objective of this study was to develop balanced mix Ndesign values for North Dakota pavements based on the HMA performance with respect to resistance to rutting, low-temperature cracking, and fatigue cracking. Project mix samples were constructed and tested based on Ndesign values of 75, 65, 55, or 50 gyrations. The sample matrix included fine aggregate angularity (FAA) values of 45, 43, and 40, representing high-, medium-, and low-volume pavements, respectively. The matrix also included the asphalt binders PG 58S-28, PG 58H-34, and PG 58H-28. An analysis of variance (ANOVA) was done on the performance results and showed that the results corresponding to the various gyration levels were significantly different and can be compared. Test results revealed that a lower number of gyrations and a higher binder content resulted in higher resistance to fatigue and thermal cracking, while rut resistance stayed above acceptable levels. Based on the test results, the authors recommend an Ndesign of 65 gyrations for the high-volume pavements and 50 gyrations for intermediate- and low-volume pavements.
{"title":"Developing Balanced Mix Design Gyrations (Ndesign) for North Dakota’s Hot-Mix Asphalt Pavements","authors":"Nabil Suleiman, Anjo Mate, D. Gedafa, Bruce Dockter","doi":"10.1177/03611981241260705","DOIUrl":"https://doi.org/10.1177/03611981241260705","url":null,"abstract":"There is a need to develop a new mix design criterion for North Dakota especially for medium- and low-volume traffic pavements, where the durability performance of the hot-mix asphalt (HMA) is of the most importance. High Ndesign numbers tend to lower the asphalt binder, thus lowering the durability of the asphalt mix. In contrast, if Ndesign is reduced, it tends to increase the asphalt binder, thus improving the durability of the asphalt mix. The main objective of this study was to develop balanced mix Ndesign values for North Dakota pavements based on the HMA performance with respect to resistance to rutting, low-temperature cracking, and fatigue cracking. Project mix samples were constructed and tested based on Ndesign values of 75, 65, 55, or 50 gyrations. The sample matrix included fine aggregate angularity (FAA) values of 45, 43, and 40, representing high-, medium-, and low-volume pavements, respectively. The matrix also included the asphalt binders PG 58S-28, PG 58H-34, and PG 58H-28. An analysis of variance (ANOVA) was done on the performance results and showed that the results corresponding to the various gyration levels were significantly different and can be compared. Test results revealed that a lower number of gyrations and a higher binder content resulted in higher resistance to fatigue and thermal cracking, while rut resistance stayed above acceptable levels. Based on the test results, the authors recommend an Ndesign of 65 gyrations for the high-volume pavements and 50 gyrations for intermediate- and low-volume pavements.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141797417","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 : 2024-07-27DOI: 10.1177/03611981241260690
N. Le, Daniel Tran, Christofer M. Harper, Roy E. Sturgill
State departments of transportation (DOTs) historically employed onsite inspectors to perform hands-on and in-person infrastructure inspections. However, with the latest technological advancements, state DOTs increasingly use technologies to complement their inspection of highway infrastructure. This study investigates common technologies used by state DOTs to inspect highway infrastructure during the construction and maintenance of highway assets. A list of 19 technologies was developed from the literature review. A national survey of 50 state DOTs was conducted to determine the most common technologies used for the inspection of highway infrastructure. The top technologies used by state DOTs to inspect highway infrastructure during construction are tablet/smart mobile devices; global navigation satellite systems (GNSS)/global positioning systems (GPS); remote sensors such as accelerometers, maturity meter sensors, or strain gauges; e-ticketing; remote cameras; and unmanned aircraft systems (UAS). The top technologies used by state DOTs to inspect highway infrastructure during maintenance of assets are geographic information systems applications, light detection and ranging/3D laser scanners, tablet/smart mobile devices, GNSS/GPS, and UAS. Six case studies with Florida, Illinois, Iowa, Minnesota, New York, and Oregon state DOTs were then conducted to verify the results from the survey questionnaire. The main inspection activities and challenges of using these technologies during construction and asset management were discussed. The findings from this study provide valuable information for state DOTs to understand how better to implement technologies for the inspection of highway infrastructure.
{"title":"Exploring Inspection Technologies for Highway Infrastructure During Construction and Asset Management","authors":"N. Le, Daniel Tran, Christofer M. Harper, Roy E. Sturgill","doi":"10.1177/03611981241260690","DOIUrl":"https://doi.org/10.1177/03611981241260690","url":null,"abstract":"State departments of transportation (DOTs) historically employed onsite inspectors to perform hands-on and in-person infrastructure inspections. However, with the latest technological advancements, state DOTs increasingly use technologies to complement their inspection of highway infrastructure. This study investigates common technologies used by state DOTs to inspect highway infrastructure during the construction and maintenance of highway assets. A list of 19 technologies was developed from the literature review. A national survey of 50 state DOTs was conducted to determine the most common technologies used for the inspection of highway infrastructure. The top technologies used by state DOTs to inspect highway infrastructure during construction are tablet/smart mobile devices; global navigation satellite systems (GNSS)/global positioning systems (GPS); remote sensors such as accelerometers, maturity meter sensors, or strain gauges; e-ticketing; remote cameras; and unmanned aircraft systems (UAS). The top technologies used by state DOTs to inspect highway infrastructure during maintenance of assets are geographic information systems applications, light detection and ranging/3D laser scanners, tablet/smart mobile devices, GNSS/GPS, and UAS. Six case studies with Florida, Illinois, Iowa, Minnesota, New York, and Oregon state DOTs were then conducted to verify the results from the survey questionnaire. The main inspection activities and challenges of using these technologies during construction and asset management were discussed. The findings from this study provide valuable information for state DOTs to understand how better to implement technologies for the inspection of highway infrastructure.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798176","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 : 2024-07-27DOI: 10.1177/03611981241263350
Ryosuke Yokoi
Studies have explored the factor of trust in autonomous cars (ACs), and it has been shown that their ability and performance are crucial for determining trust. However, little is known about the effects of minor errors without involving negative consequences such as property damage and fatalities. People are likely to expect automation technologies to perform better than humans. It was, therefore, hypothesized that minor errors would destroy expectations and significantly decrease trust in ACs. This study aimed to investigate whether minor errors have a more negative effect on trust in ACs than in human drivers. Two experiments were conducted ( N = 821) in Japan. Two independent variables were manipulated: agent (AC and human) and error (error and no-error). Some participants were shown videos depicting ACs and human drivers making minor errors, such as taking a longer time to park (Experiment 1) and delaying to take off when traffic lights turned green (Experiment 2). These minor errors did not violate Japanese traffic laws. Others watched videos in which no errors occurred. The results of the two-way analysis of variance did not show evidence that the agent type modulated the negative effects of these minor errors on trust. Minor errors did not lead to a significant difference in trust levels between ACs and human drivers. This study also indicated that people expected ACs to not make more errors than humans did. However, these expectations did not increase trust in ACs. The findings also suggest that minor errors are unlikely to cause an underestimation of ACs’ capabilities.
{"title":"Trust in Autonomous Cars Does Not Largely Differ from Trust in Human Drivers when They Make Minor Errors","authors":"Ryosuke Yokoi","doi":"10.1177/03611981241263350","DOIUrl":"https://doi.org/10.1177/03611981241263350","url":null,"abstract":"Studies have explored the factor of trust in autonomous cars (ACs), and it has been shown that their ability and performance are crucial for determining trust. However, little is known about the effects of minor errors without involving negative consequences such as property damage and fatalities. People are likely to expect automation technologies to perform better than humans. It was, therefore, hypothesized that minor errors would destroy expectations and significantly decrease trust in ACs. This study aimed to investigate whether minor errors have a more negative effect on trust in ACs than in human drivers. Two experiments were conducted ( N = 821) in Japan. Two independent variables were manipulated: agent (AC and human) and error (error and no-error). Some participants were shown videos depicting ACs and human drivers making minor errors, such as taking a longer time to park (Experiment 1) and delaying to take off when traffic lights turned green (Experiment 2). These minor errors did not violate Japanese traffic laws. Others watched videos in which no errors occurred. The results of the two-way analysis of variance did not show evidence that the agent type modulated the negative effects of these minor errors on trust. Minor errors did not lead to a significant difference in trust levels between ACs and human drivers. This study also indicated that people expected ACs to not make more errors than humans did. However, these expectations did not increase trust in ACs. The findings also suggest that minor errors are unlikely to cause an underestimation of ACs’ capabilities.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798250","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 : 2024-07-27DOI: 10.1177/03611981241255370
Abhik J. Borthakur, Arturo Espinoza-Luque, Kelly L. Smith, Kurt Smith, Michael Short
The Illinois Department of Transportation (IDOT) District 3 office sought a comprehensive, long-term plan for fiscally managing a 36-mi portion of I-39 in LaSalle County, Illinois. To accomplish this, IDOT initiated a study to evaluate the historical and current conditions of the continuously reinforced concrete pavement constituting I-39, determine the pavement needs, and develop cost-effective, long-term strategy recommendations for keeping the facility at an acceptable serviceability level over an extended period of time. The project consisted of three phases: (1) review and analysis of construction, maintenance and repair, and time-series pavement condition data; (2) supplemental field data collection and analysis; and (3) pavement strategy development and cost analyses. Using the historical records and performance data, the project was subdivided into segments based on unique pavement conditions and needs. An optimal pavement strategy was developed for each road segment, reflecting the best theoretical solution, based on performance data and pavement management guidance. Two suboptimal strategies were then developed, one reflecting a preventive treatment approach and the other an aggressive treatment approach. Each strategy was defined by a series of treatments at different times, covering a 50-year analysis period. The strategy cost analyses included the computation of life-cycle costs and benefit–cost ratios for each strategy alternative, and a risk assessment of the suboptimal strategies. The cost analysis results provided IDOT District 3 with critical information for selecting the most economical set of long-term strategies for keeping the I-39 pavement segments serviceable for the traveling public over the 50-year planning period.
{"title":"Strategies for Managing an In-Service Continuously Reinforced Concrete Pavement in Illinois","authors":"Abhik J. Borthakur, Arturo Espinoza-Luque, Kelly L. Smith, Kurt Smith, Michael Short","doi":"10.1177/03611981241255370","DOIUrl":"https://doi.org/10.1177/03611981241255370","url":null,"abstract":"The Illinois Department of Transportation (IDOT) District 3 office sought a comprehensive, long-term plan for fiscally managing a 36-mi portion of I-39 in LaSalle County, Illinois. To accomplish this, IDOT initiated a study to evaluate the historical and current conditions of the continuously reinforced concrete pavement constituting I-39, determine the pavement needs, and develop cost-effective, long-term strategy recommendations for keeping the facility at an acceptable serviceability level over an extended period of time. The project consisted of three phases: (1) review and analysis of construction, maintenance and repair, and time-series pavement condition data; (2) supplemental field data collection and analysis; and (3) pavement strategy development and cost analyses. Using the historical records and performance data, the project was subdivided into segments based on unique pavement conditions and needs. An optimal pavement strategy was developed for each road segment, reflecting the best theoretical solution, based on performance data and pavement management guidance. Two suboptimal strategies were then developed, one reflecting a preventive treatment approach and the other an aggressive treatment approach. Each strategy was defined by a series of treatments at different times, covering a 50-year analysis period. The strategy cost analyses included the computation of life-cycle costs and benefit–cost ratios for each strategy alternative, and a risk assessment of the suboptimal strategies. The cost analysis results provided IDOT District 3 with critical information for selecting the most economical set of long-term strategies for keeping the I-39 pavement segments serviceable for the traveling public over the 50-year planning period.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141797466","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 : 2024-07-27DOI: 10.1177/03611981241260699
Thibault Charlottin, Silvia Varotto, Bruno Jeanneret, Sylvain Gillet, Christine Buisson
Vehicles equipped with adaptive cruise control (ACC) systems are expected to improve traffic safety and decrease fuel consumption. Recent experimental studies have shown that ACC leads to string instability in the case of platooning and can, therefore, result in higher energy needs compared with a platoon of human-driven vehicles (HDV). However, the impact of ACC on fuel consumption in the case of platooning and the global impact of ACC fuel overconsumption in traffic are not known yet. This study examines the impact of ACC systems on traffic fuel consumption using experimental data and traffic records. In this study, we inject the speed profiles of ACC and HDV platoons that follow a similar leader trajectory into an engine bench. Then, we identify the event that leads to an overconsumption of fuel in the case of platooning. The results of the engine bench show that only ACC platoons of six or more vehicles with a short time-gap setting consume more fuel than HDV platoons. Using HighD and ExiD records, we detect if the events leading to fuel overconsumption often happen in traffic. The results on HighD and ExiD show that such an event happens once out of 1,250 episodes if we divide the time into episodes of 15 s. This shows that, even if fuel overconsumption exists in specific cases, those cases are actually too rare in traffic to affect global fuel consumption.
{"title":"Fuel Consumption of Adaptive Cruise Control Platoons: Bench Experiments and Data-Driven Estimation for Real Traffic","authors":"Thibault Charlottin, Silvia Varotto, Bruno Jeanneret, Sylvain Gillet, Christine Buisson","doi":"10.1177/03611981241260699","DOIUrl":"https://doi.org/10.1177/03611981241260699","url":null,"abstract":"Vehicles equipped with adaptive cruise control (ACC) systems are expected to improve traffic safety and decrease fuel consumption. Recent experimental studies have shown that ACC leads to string instability in the case of platooning and can, therefore, result in higher energy needs compared with a platoon of human-driven vehicles (HDV). However, the impact of ACC on fuel consumption in the case of platooning and the global impact of ACC fuel overconsumption in traffic are not known yet. This study examines the impact of ACC systems on traffic fuel consumption using experimental data and traffic records. In this study, we inject the speed profiles of ACC and HDV platoons that follow a similar leader trajectory into an engine bench. Then, we identify the event that leads to an overconsumption of fuel in the case of platooning. The results of the engine bench show that only ACC platoons of six or more vehicles with a short time-gap setting consume more fuel than HDV platoons. Using HighD and ExiD records, we detect if the events leading to fuel overconsumption often happen in traffic. The results on HighD and ExiD show that such an event happens once out of 1,250 episodes if we divide the time into episodes of 15 s. This shows that, even if fuel overconsumption exists in specific cases, those cases are actually too rare in traffic to affect global fuel consumption.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798381","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 : 2024-07-27DOI: 10.1177/03611981241255600
Ethan M. Ray, C. Carrigan, C. Plaxico
The “New England steel bridge rail” family of bridge rails, which were designed and tested under the auspices of the New England Transportation Consortium (NETC), has been installed on roadways in New England for more than 20 years. Recently, guidelines for the assembly and analysis of in-service performance evaluation (ISPE) data were published in NCHRP Report 1010. An ISPE using the NCHRP Report 1010 data collection and analysis methodology was conducted for the state of Maine. This paper summarizes those findings. The crash dataset used in this ISPE included 99 crash cases that occurred over an 8-year period on public roads within the state of Maine. The objective of this ISPE was to evaluate the field performance of the NETC bridge railings with regard to occupant risk, structural adequacy, and postimpact vehicle trajectory under real-world conditions. The Maine ISPE demonstrated that the NETC bridge railings had similar or better field performance than other similar systems across all three performance outcomes. This field performance demonstrated the crashworthiness of the NETC bridge railings and supports their continued use. This paper summarizes the results of this ISPE.
{"title":"Demonstrating Crashworthiness of Bridge Railings in Maine","authors":"Ethan M. Ray, C. Carrigan, C. Plaxico","doi":"10.1177/03611981241255600","DOIUrl":"https://doi.org/10.1177/03611981241255600","url":null,"abstract":"The “New England steel bridge rail” family of bridge rails, which were designed and tested under the auspices of the New England Transportation Consortium (NETC), has been installed on roadways in New England for more than 20 years. Recently, guidelines for the assembly and analysis of in-service performance evaluation (ISPE) data were published in NCHRP Report 1010. An ISPE using the NCHRP Report 1010 data collection and analysis methodology was conducted for the state of Maine. This paper summarizes those findings. The crash dataset used in this ISPE included 99 crash cases that occurred over an 8-year period on public roads within the state of Maine. The objective of this ISPE was to evaluate the field performance of the NETC bridge railings with regard to occupant risk, structural adequacy, and postimpact vehicle trajectory under real-world conditions. The Maine ISPE demonstrated that the NETC bridge railings had similar or better field performance than other similar systems across all three performance outcomes. This field performance demonstrated the crashworthiness of the NETC bridge railings and supports their continued use. This paper summarizes the results of this ISPE.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141797566","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 : 2024-07-27DOI: 10.1177/03611981241257504
Rahul Reddy Banapuram, Thavamani Andiyappan, K. Kuna, Muppireddy Amaranatha Reddy, Arghya Deb
The objective of the present study is twofold: firstly, to evaluate the influence of asphalt emulsion properties on the fluidity characteristics of cement asphalt mortar (CAM) for high-speed railway (HSR) track systems; and secondly, to propose a testing protocol that effectively differentiates the asphalt emulsions suitable for CAM with respect to fluidity requirement, considering specific requirements for the application. The study involved assessing CAM fluidity under various emulsion formulation variables, including the pH, residual asphalt content, and emulsifier dosage. In addition, three different test methods were evaluated for their suitability as the protocol for asphalt emulsions evaluation for CAM production in HSR applications. The results showed that the pH of the asphalt emulsion significantly affects the fluidity of the CAM, with cationic emulsions demonstrating less stability because of high alkaline conditions of CAM, while anionic/non-ionic emulsions exhibited stable fluidity. Fluidity in CAM is observed when an asphalt emulsion possesses an optimal micelle concentration, which effectively resists coagulation. The findings emphasize the importance of considering both upper and lower limits for residual asphalt content in emulsion specifications for CAM production. Emulsifier dosage also played a role, with high emulsifier dosages leading to high fluidity in CAM. The study introduced a fluidity ratio test as a suitable method for selecting asphalt emulsions for CAM production for HSR track systems.
{"title":"Influence of Asphalt Emulsion Formulation Parameters on the Fluidity of Cement Asphalt Mortar for High-Speed Rail Tracks","authors":"Rahul Reddy Banapuram, Thavamani Andiyappan, K. Kuna, Muppireddy Amaranatha Reddy, Arghya Deb","doi":"10.1177/03611981241257504","DOIUrl":"https://doi.org/10.1177/03611981241257504","url":null,"abstract":"The objective of the present study is twofold: firstly, to evaluate the influence of asphalt emulsion properties on the fluidity characteristics of cement asphalt mortar (CAM) for high-speed railway (HSR) track systems; and secondly, to propose a testing protocol that effectively differentiates the asphalt emulsions suitable for CAM with respect to fluidity requirement, considering specific requirements for the application. The study involved assessing CAM fluidity under various emulsion formulation variables, including the pH, residual asphalt content, and emulsifier dosage. In addition, three different test methods were evaluated for their suitability as the protocol for asphalt emulsions evaluation for CAM production in HSR applications. The results showed that the pH of the asphalt emulsion significantly affects the fluidity of the CAM, with cationic emulsions demonstrating less stability because of high alkaline conditions of CAM, while anionic/non-ionic emulsions exhibited stable fluidity. Fluidity in CAM is observed when an asphalt emulsion possesses an optimal micelle concentration, which effectively resists coagulation. The findings emphasize the importance of considering both upper and lower limits for residual asphalt content in emulsion specifications for CAM production. Emulsifier dosage also played a role, with high emulsifier dosages leading to high fluidity in CAM. The study introduced a fluidity ratio test as a suitable method for selecting asphalt emulsions for CAM production for HSR track systems.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798041","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 : 2024-07-27DOI: 10.1177/03611981241262316
Lili Zheng, Yanlin Li, T. Ding, Yuying Wang, Fanyun Meng
To cope with the increasing number of road traffic crashes, it is critical to develop a driver assistance system that can provide early warning for vehicle collisions and control the vehicle at critical moments. However, to achieve this function, the driver assistance system must proactively understand drivers’ preferences and predict their risk avoidance behavior in risk scenarios, an area that currently lacks sufficient research. To address this issue, this study proposes a method for modeling microscopic risk avoidance behavior for homogeneous groups of drivers. Firstly, the risk field theory is established to achieve the basic driving risk assessment. Subsequently, a macro–micro collision-tendency probability calculation model is constructed to correct the basic driving risk values and obtain more accurate risk assessment results. Finally, a risk avoidance behavior model is developed by combining drivers’ risk response behavior and the psychology of desired speed pursuit. This study uses natural driving data for model validation. The results imply that the risk assessment indicator proposed in this study can reflect the driving risk under different risk phases. The risk avoidance behavior model accurately identifies vehicle acceleration fluctuations and matches drivers’ avoidance motivation in risk scenarios. In addition, the model parameters calibration results reveal significant differences among different driving groups; for example, risk perception and desired speed. This study aims to deepen researchers’ understanding of drivers’ risk avoidance behavior for designing driver assistance systems and road safety management.
{"title":"Modeling and Analysis of Microscopic Risk Avoidance Behavior of Homogeneous Driver Groups Under Risk Scenarios","authors":"Lili Zheng, Yanlin Li, T. Ding, Yuying Wang, Fanyun Meng","doi":"10.1177/03611981241262316","DOIUrl":"https://doi.org/10.1177/03611981241262316","url":null,"abstract":"To cope with the increasing number of road traffic crashes, it is critical to develop a driver assistance system that can provide early warning for vehicle collisions and control the vehicle at critical moments. However, to achieve this function, the driver assistance system must proactively understand drivers’ preferences and predict their risk avoidance behavior in risk scenarios, an area that currently lacks sufficient research. To address this issue, this study proposes a method for modeling microscopic risk avoidance behavior for homogeneous groups of drivers. Firstly, the risk field theory is established to achieve the basic driving risk assessment. Subsequently, a macro–micro collision-tendency probability calculation model is constructed to correct the basic driving risk values and obtain more accurate risk assessment results. Finally, a risk avoidance behavior model is developed by combining drivers’ risk response behavior and the psychology of desired speed pursuit. This study uses natural driving data for model validation. The results imply that the risk assessment indicator proposed in this study can reflect the driving risk under different risk phases. The risk avoidance behavior model accurately identifies vehicle acceleration fluctuations and matches drivers’ avoidance motivation in risk scenarios. In addition, the model parameters calibration results reveal significant differences among different driving groups; for example, risk perception and desired speed. This study aims to deepen researchers’ understanding of drivers’ risk avoidance behavior for designing driver assistance systems and road safety management.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141798255","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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