Pub Date : 2024-01-03DOI: 10.1177/03611981231215334
Lan Huang, Zhibin Ren, Xianghai Meng
This study aimed to explore the impacting mechanism of macro- and micro-factors and multi-scale synergy on drivers’ merging behaviors in the highway work zone, and then to facilitate future merging prediction research. The merging behavior, requiring drivers to detect adjacent vehicles and real-time traffic conditions simultaneously, is a complex cognitive process. Previous studies have mainly focused on the stable impacts of limited factors on merging probability, but ignored the varying states and drivers’ performance. Status-changing positions in the whole merging process were first identified by constructing and analyzing the relationship between running speed and distance from the construction area. Subsequently, the interaction analysis was conducted among the multi-scale traffic factors, utilizing optimized logistic models and interaction estimates, thus establishing macro- and micro-factor connections. Besides, the marginal effect was calculated to analyze the fluctuation degree of these connections. Finally, a multilevel identification framework was proposed, whose effectiveness and practicality were validated using 744 naturalistic vehicular trajectories from a real highway work area. At different positions, drivers are affected by various factors to varying degrees. While approaching the construction area, drivers become more passive, thus trying to avoid rear-ending the lead vehicle but ignoring the lag vehicle. Besides, traffic volume also affects drivers’ merging decisions by confusing their cognition toward the time headway. This research indicates that dynamic interaction effects between multi-scale factors could provide far-reaching benefits for lane-changing prediction. The findings provide a basis for formulating traffic management policies and constructing driving assistance systems.
{"title":"Changing Regularity of the Interaction Effects of Multi-Scale Factors on Drivers’ Merging Behaviors in the Highway Work Zone","authors":"Lan Huang, Zhibin Ren, Xianghai Meng","doi":"10.1177/03611981231215334","DOIUrl":"https://doi.org/10.1177/03611981231215334","url":null,"abstract":"This study aimed to explore the impacting mechanism of macro- and micro-factors and multi-scale synergy on drivers’ merging behaviors in the highway work zone, and then to facilitate future merging prediction research. The merging behavior, requiring drivers to detect adjacent vehicles and real-time traffic conditions simultaneously, is a complex cognitive process. Previous studies have mainly focused on the stable impacts of limited factors on merging probability, but ignored the varying states and drivers’ performance. Status-changing positions in the whole merging process were first identified by constructing and analyzing the relationship between running speed and distance from the construction area. Subsequently, the interaction analysis was conducted among the multi-scale traffic factors, utilizing optimized logistic models and interaction estimates, thus establishing macro- and micro-factor connections. Besides, the marginal effect was calculated to analyze the fluctuation degree of these connections. Finally, a multilevel identification framework was proposed, whose effectiveness and practicality were validated using 744 naturalistic vehicular trajectories from a real highway work area. At different positions, drivers are affected by various factors to varying degrees. While approaching the construction area, drivers become more passive, thus trying to avoid rear-ending the lead vehicle but ignoring the lag vehicle. Besides, traffic volume also affects drivers’ merging decisions by confusing their cognition toward the time headway. This research indicates that dynamic interaction effects between multi-scale factors could provide far-reaching benefits for lane-changing prediction. The findings provide a basis for formulating traffic management policies and constructing driving assistance systems.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139451626","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 : 2023-12-31DOI: 10.1177/03611981231213879
Xiaoxi Cai, Yanping Xiao, Zhang Lei
Identifying the causes of congestion is the key to solving traffic congestion. To improve the efficiency of congestion control, this paper establishes a congestion cause identification method based on the three stages of pattern recognition, source tracing, and cause discrimination. The K-means algorithm was proposed to calculate the frequency threshold of recurrent congestion, trace the sources of congestion according to the rules of congestion propagation time sequences, build a congestion fault tree based on causal logic relationships, and determine the occurrence probability and importance of each cause by using the expert scoring method and cloud model. The test results showed that the method is promising and could provide support for scientific congestion control.
{"title":"Traffic Congestion Cause Identification Method for Urban Main Roads","authors":"Xiaoxi Cai, Yanping Xiao, Zhang Lei","doi":"10.1177/03611981231213879","DOIUrl":"https://doi.org/10.1177/03611981231213879","url":null,"abstract":"Identifying the causes of congestion is the key to solving traffic congestion. To improve the efficiency of congestion control, this paper establishes a congestion cause identification method based on the three stages of pattern recognition, source tracing, and cause discrimination. The K-means algorithm was proposed to calculate the frequency threshold of recurrent congestion, trace the sources of congestion according to the rules of congestion propagation time sequences, build a congestion fault tree based on causal logic relationships, and determine the occurrence probability and importance of each cause by using the expert scoring method and cloud model. The test results showed that the method is promising and could provide support for scientific congestion control.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139131927","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 : 2023-12-29DOI: 10.1177/03611981231214519
Nabanita Roy, Anil Kumar Baditha, Soumyarup Biswas, K. Kuna
The objective of this study was to propose an image processing-based index for measuring pavement macrotexture at the network level. This index enables macrotexture to be measured easily and inexpensively using images collected at traffic speed. The study involved collecting pavement surface images at a constant traffic speed on a test section specifically designed and constructed for this purpose, with three surface course mixes that are commonly used in India, namely, bituminous concrete, stone matrix asphalt, and gap-graded rubberized bituminous mix. Additionally, macrotexture data with regard to mean texture depth (MTD) from the sand patch test and mean profile depth (MPD) from laser sensor-based measurements were obtained at the locations where the images were captured. The surface macrotexture index (SMI), which was derived from wavelet transform-based image texture analysis, was compared with the MTD and MPD data. The results showed that the SMI is an accurate indicator of pavement surface macrotexture. In addition, the study showcased the application of an unsupervised machine learning algorithm to identify and replace outliers in the SMI data that resulted from isolated spots with dirt, pavement markings, and wet surfaces. The research also established relationships between the proposed SMI and MTD/MPD. These relationships are reliable and can be used to predict the commonly used pavement surface construction quality measure MTD and the network-level skid resistance indicator MPD.
{"title":"Measuring the Macrotexture of Pavement Surface Using an Image Processing Technique","authors":"Nabanita Roy, Anil Kumar Baditha, Soumyarup Biswas, K. Kuna","doi":"10.1177/03611981231214519","DOIUrl":"https://doi.org/10.1177/03611981231214519","url":null,"abstract":"The objective of this study was to propose an image processing-based index for measuring pavement macrotexture at the network level. This index enables macrotexture to be measured easily and inexpensively using images collected at traffic speed. The study involved collecting pavement surface images at a constant traffic speed on a test section specifically designed and constructed for this purpose, with three surface course mixes that are commonly used in India, namely, bituminous concrete, stone matrix asphalt, and gap-graded rubberized bituminous mix. Additionally, macrotexture data with regard to mean texture depth (MTD) from the sand patch test and mean profile depth (MPD) from laser sensor-based measurements were obtained at the locations where the images were captured. The surface macrotexture index (SMI), which was derived from wavelet transform-based image texture analysis, was compared with the MTD and MPD data. The results showed that the SMI is an accurate indicator of pavement surface macrotexture. In addition, the study showcased the application of an unsupervised machine learning algorithm to identify and replace outliers in the SMI data that resulted from isolated spots with dirt, pavement markings, and wet surfaces. The research also established relationships between the proposed SMI and MTD/MPD. These relationships are reliable and can be used to predict the commonly used pavement surface construction quality measure MTD and the network-level skid resistance indicator MPD.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139145617","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 : 2023-12-28DOI: 10.1177/03611981231215342
Francisco Javier Bonachera Martin, Sofia Puerto Tchemodanova, Alexandra Willoughby, Linda M. Krueger, Daniel Baxter, Brian Kozy, Francesco Russo
Because of the perceived risk of fracture critical members (FCMs) in steel bridges, hands-on inspection cycles are mandated, resulting in high maintenance costs. This paper describes the redundancy evaluation of three twin tub girder bridges with FCM designations. Several failure scenarios of primary members are considered using refined finite element analysis of each structure to determine whether fractures result in collapse or loss of serviceability of the bridge. The analysis follows the American Association of State Highway and Transportation Officials Guide Specifications for Analysis and Identification of Fracture Critical Members and System Redundant Members. Based on the outcomes of these analyses, the feasibility of retrofit alternatives is assessed with the purpose of reclassifying FCMs as system redundant members and precluding hands-on inspection requirements.
{"title":"Retrofits in Twin Tub Girder Bridges for System-Level Redundancy","authors":"Francisco Javier Bonachera Martin, Sofia Puerto Tchemodanova, Alexandra Willoughby, Linda M. Krueger, Daniel Baxter, Brian Kozy, Francesco Russo","doi":"10.1177/03611981231215342","DOIUrl":"https://doi.org/10.1177/03611981231215342","url":null,"abstract":"Because of the perceived risk of fracture critical members (FCMs) in steel bridges, hands-on inspection cycles are mandated, resulting in high maintenance costs. This paper describes the redundancy evaluation of three twin tub girder bridges with FCM designations. Several failure scenarios of primary members are considered using refined finite element analysis of each structure to determine whether fractures result in collapse or loss of serviceability of the bridge. The analysis follows the American Association of State Highway and Transportation Officials Guide Specifications for Analysis and Identification of Fracture Critical Members and System Redundant Members. Based on the outcomes of these analyses, the feasibility of retrofit alternatives is assessed with the purpose of reclassifying FCMs as system redundant members and precluding hands-on inspection requirements.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139149881","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 : 2023-12-28DOI: 10.1177/03611981231215255
Yonghui Zhang, Zhiping Hu, Yuchao Fan, Feng Deng, Zhiyuan Sun
Large-span tunnels often encounter large deformation and failure when crossing layered sedimentary structures, particularly sedimentary structures that have been steeply inclined by geologic processes. This paper takes the Yongle Tunnel on the G544 line in Jiuzhaigou County, Sichuan Province, China, as an example and analyzes the deformation and failure characteristics of the tunnel through a field investigation and field test. Then, through theoretical analysis and numerical simulation, the influence of the section size, rock dip angle, and rock thickness on the deformation of the tunnel is analyzed to reveal the tunnel’s deformation mechanism. Finally, effective control measures are put forward based on the examination. The results show that the tunnel suffers from unobvious asymmetric deformation. The convergence deformation of the tunnel side wall and the sensitivity to the section size are much larger than the vault settlement and haunch convergence. The large deformation of the tunnel is caused by improper construction methods and weak structural planes. The deformation of the tunnel was significantly reduced by adapting the center diaphragm method, with anchors placed as vertically as possible to the rock or at large intersection angles and by strengthening the radial grouting of the surrounding rock. The research results can provide a reference for tunnels in similar strata.
{"title":"Deformation Mechanism and Control Measures of Large-Span Tunnels in Steep Layered Surrounding Rock","authors":"Yonghui Zhang, Zhiping Hu, Yuchao Fan, Feng Deng, Zhiyuan Sun","doi":"10.1177/03611981231215255","DOIUrl":"https://doi.org/10.1177/03611981231215255","url":null,"abstract":"Large-span tunnels often encounter large deformation and failure when crossing layered sedimentary structures, particularly sedimentary structures that have been steeply inclined by geologic processes. This paper takes the Yongle Tunnel on the G544 line in Jiuzhaigou County, Sichuan Province, China, as an example and analyzes the deformation and failure characteristics of the tunnel through a field investigation and field test. Then, through theoretical analysis and numerical simulation, the influence of the section size, rock dip angle, and rock thickness on the deformation of the tunnel is analyzed to reveal the tunnel’s deformation mechanism. Finally, effective control measures are put forward based on the examination. The results show that the tunnel suffers from unobvious asymmetric deformation. The convergence deformation of the tunnel side wall and the sensitivity to the section size are much larger than the vault settlement and haunch convergence. The large deformation of the tunnel is caused by improper construction methods and weak structural planes. The deformation of the tunnel was significantly reduced by adapting the center diaphragm method, with anchors placed as vertically as possible to the rock or at large intersection angles and by strengthening the radial grouting of the surrounding rock. The research results can provide a reference for tunnels in similar strata.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139152726","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 : 2023-12-26DOI: 10.1177/03611981231214518
Jessica B. Cicchino, Neil K. Chaudhary, Mark G. Solomon
Many cities limit the top speeds of shared e-scooters, but little is known about how these policies affect user behavior. This study measured speeds and observed use of roads, sidewalks, and bike lanes for 2,004 e-scooter riders in Washington, D.C., where shared e-scooters were equipped with speed governors that limited their speed to 10 mph, and Austin, TX, where the limit was 20 mph. At locations without bike lanes, riders in Washington were 51% more likely to ride on sidewalks than in Austin when accounting for environmental and rider characteristics. Over 80% of e-scooter users rode in bike lanes in both cities when they were available. Although the mean riding speed on sidewalks was not significantly higher in Austin than in Washington, demonstrating self-regulation of speed on sidewalks, the percentage of e-scooter riders traveling on sidewalks at speeds ≥10 mph (41% in Austin versus 17% in Washington) or ≥15 mph (9% in Austin versus <1% in Washington) was higher in Austin. Increased sidewalk riding associated with setting shared e-scooter speed limiters to 10 mph could potentially lead to more interactions with pedestrians, but lower e-scooter speeds at the high end of the distribution may mitigate injury risk to them. Bike lanes could provide space for e-scooters to ride where their speeds would more closely match other users. Future refinements to technology to identify sidewalk riding more accurately could potentially allow maximum e-scooter speeds to be adjusted to mix with pedestrians on sidewalks and cyclists in bike lanes.
{"title":"How Are E-Scooter Speed-Limiter Settings Associated with User Behavior? Observed Speeds and Road, Sidewalk, and Bike Lane Use in Austin, TX, and Washington, D.C.","authors":"Jessica B. Cicchino, Neil K. Chaudhary, Mark G. Solomon","doi":"10.1177/03611981231214518","DOIUrl":"https://doi.org/10.1177/03611981231214518","url":null,"abstract":"Many cities limit the top speeds of shared e-scooters, but little is known about how these policies affect user behavior. This study measured speeds and observed use of roads, sidewalks, and bike lanes for 2,004 e-scooter riders in Washington, D.C., where shared e-scooters were equipped with speed governors that limited their speed to 10 mph, and Austin, TX, where the limit was 20 mph. At locations without bike lanes, riders in Washington were 51% more likely to ride on sidewalks than in Austin when accounting for environmental and rider characteristics. Over 80% of e-scooter users rode in bike lanes in both cities when they were available. Although the mean riding speed on sidewalks was not significantly higher in Austin than in Washington, demonstrating self-regulation of speed on sidewalks, the percentage of e-scooter riders traveling on sidewalks at speeds ≥10 mph (41% in Austin versus 17% in Washington) or ≥15 mph (9% in Austin versus <1% in Washington) was higher in Austin. Increased sidewalk riding associated with setting shared e-scooter speed limiters to 10 mph could potentially lead to more interactions with pedestrians, but lower e-scooter speeds at the high end of the distribution may mitigate injury risk to them. Bike lanes could provide space for e-scooters to ride where their speeds would more closely match other users. Future refinements to technology to identify sidewalk riding more accurately could potentially allow maximum e-scooter speeds to be adjusted to mix with pedestrians on sidewalks and cyclists in bike lanes.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139155312","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 : 2023-12-26DOI: 10.1177/03611981231213648
Xueguang Ma, Ce Jiang, Zhao Zhang
High-speed rail (HSR) and aviation have played an important role in shaping urban connections and building urban networks. However, with the continuous expansion of the scale of HSR, the competition between the two has become increasingly fierce, and HSR has gradually been substituted for aviation in some regions. Therefore, based on HSR flow and airline flow data, we depicted the spatio-temporal evolution pattern of China’s urban network from 2017 to 2021 by constructing the HSR–aviation composite network, then identified the spatial scope and network form of the substitution of HSR for aviation through classifying the four types of segments, and analyzed the influencing factors of this substitution effect. The results showed that the spatial form of the HSR–aviation composite network is “spindle-shaped” and has a right-skewness distribution; the spatial scope of HSR completely or partially substituting for aviation is mainly distributed in the “diamond-shaped” space with Beijing–Shanghai–Guangzhou–Chengdu as the apex; and 0–770 km is the absolute advantage distance range of HSR. Moreover, the scale expansion of the composite network, the comparative advantages of HSR in shaping the urban network, the personal travel preference for HSR, and the distance between cities and city attributes are the main factors that make HSR a substitute for aviation.
{"title":"Spatio-Temporal Pattern of China’s Urban Network Under the Substitution Effect of High-Speed Rail on Aviation","authors":"Xueguang Ma, Ce Jiang, Zhao Zhang","doi":"10.1177/03611981231213648","DOIUrl":"https://doi.org/10.1177/03611981231213648","url":null,"abstract":"High-speed rail (HSR) and aviation have played an important role in shaping urban connections and building urban networks. However, with the continuous expansion of the scale of HSR, the competition between the two has become increasingly fierce, and HSR has gradually been substituted for aviation in some regions. Therefore, based on HSR flow and airline flow data, we depicted the spatio-temporal evolution pattern of China’s urban network from 2017 to 2021 by constructing the HSR–aviation composite network, then identified the spatial scope and network form of the substitution of HSR for aviation through classifying the four types of segments, and analyzed the influencing factors of this substitution effect. The results showed that the spatial form of the HSR–aviation composite network is “spindle-shaped” and has a right-skewness distribution; the spatial scope of HSR completely or partially substituting for aviation is mainly distributed in the “diamond-shaped” space with Beijing–Shanghai–Guangzhou–Chengdu as the apex; and 0–770 km is the absolute advantage distance range of HSR. Moreover, the scale expansion of the composite network, the comparative advantages of HSR in shaping the urban network, the personal travel preference for HSR, and the distance between cities and city attributes are the main factors that make HSR a substitute for aviation.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139155155","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 : 2023-12-26DOI: 10.1177/03611981231214521
Jiazu Zhou, Tian-tian Dong, Feng Zhu
In linear stability analysis, some unrealistic assumptions (e.g., small and long wavelength disturbance) are made for the derivation of the transfer function, which may result in an inaccurate estimation of disturbance growth rate and incorrect judgment of traffic stability. To gain more insights into the relaxation of assumptions on disturbance, this paper studies the effect of disturbance magnitude and frequency on the accuracy of disturbance growth rate estimation and the applicability of transfer function to traffic stability. The disturbance growth rates of several car-following (CF) models, including both linear and nonlinear CF models, are examined through two-vehicle simulations. The calibrated growth rate is then verified with a simulation involving a long vehicle platoon. The simulation results demonstrate that the calibrated growth rate from a two-vehicle CF pair is applicable to predict the disturbance magnitude of a long platoon. In addition, a concave growth pattern is observed, for which a novel explanation is provided based on the traditional deterministic CF model for the first time.
{"title":"Applicability of Transfer Function to Disturbance Growth Estimation and Traffic Stability","authors":"Jiazu Zhou, Tian-tian Dong, Feng Zhu","doi":"10.1177/03611981231214521","DOIUrl":"https://doi.org/10.1177/03611981231214521","url":null,"abstract":"In linear stability analysis, some unrealistic assumptions (e.g., small and long wavelength disturbance) are made for the derivation of the transfer function, which may result in an inaccurate estimation of disturbance growth rate and incorrect judgment of traffic stability. To gain more insights into the relaxation of assumptions on disturbance, this paper studies the effect of disturbance magnitude and frequency on the accuracy of disturbance growth rate estimation and the applicability of transfer function to traffic stability. The disturbance growth rates of several car-following (CF) models, including both linear and nonlinear CF models, are examined through two-vehicle simulations. The calibrated growth rate is then verified with a simulation involving a long vehicle platoon. The simulation results demonstrate that the calibrated growth rate from a two-vehicle CF pair is applicable to predict the disturbance magnitude of a long platoon. In addition, a concave growth pattern is observed, for which a novel explanation is provided based on the traditional deterministic CF model for the first time.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139155244","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 : 2023-12-26DOI: 10.1177/03611981231213874
Dongxu Chen, Shuai Tang, Yu Lin, Xudong Li, Zhongzhen Yang
To reduce commuting expenses incurred by suburban employers and their urban employees, this paper proposes the operation of commuter buses by an employer alliance and builds a bi-level programming model to optimize their operation. The upper model determines the composition of the alliance with the objective of minimizing total commuting expenses. The lower model optimizes the commuter bus routes so as to minimize the total commuting expenses of the alliance through a consideration of differences in the value of employees’ time. We fairly allocate total operating costs among alliance members based on cooperative game theory, which reinforces the optimized alliance’s stability. This paper then takes Meishan District in Ningbo as a numerical case study. The analysis shows the following: (1) under the alliance model, the total commuting expenses of three allied employers will be reduced by 8.09% per day; (2) the total commuting time of employees can be reduced by 3.75% per day; moreover, (3) the spatial distribution of the bus stops has a significant impact on employers’ willingness to participate in an alliance as opposed to operating an independent commuter bus service. Specifically, the farther dispersed the bus stops and the fewer the employees at each stop, the greater the likelihood that the employer will participate in an alliance.
{"title":"Alliance or Independence? Optimal Operation of Commuter Buses by Suburban Employers Based on Cooperative Game Theory","authors":"Dongxu Chen, Shuai Tang, Yu Lin, Xudong Li, Zhongzhen Yang","doi":"10.1177/03611981231213874","DOIUrl":"https://doi.org/10.1177/03611981231213874","url":null,"abstract":"To reduce commuting expenses incurred by suburban employers and their urban employees, this paper proposes the operation of commuter buses by an employer alliance and builds a bi-level programming model to optimize their operation. The upper model determines the composition of the alliance with the objective of minimizing total commuting expenses. The lower model optimizes the commuter bus routes so as to minimize the total commuting expenses of the alliance through a consideration of differences in the value of employees’ time. We fairly allocate total operating costs among alliance members based on cooperative game theory, which reinforces the optimized alliance’s stability. This paper then takes Meishan District in Ningbo as a numerical case study. The analysis shows the following: (1) under the alliance model, the total commuting expenses of three allied employers will be reduced by 8.09% per day; (2) the total commuting time of employees can be reduced by 3.75% per day; moreover, (3) the spatial distribution of the bus stops has a significant impact on employers’ willingness to participate in an alliance as opposed to operating an independent commuter bus service. Specifically, the farther dispersed the bus stops and the fewer the employees at each stop, the greater the likelihood that the employer will participate in an alliance.","PeriodicalId":309251,"journal":{"name":"Transportation Research Record: Journal of the Transportation Research Board","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139155371","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 : 2023-12-26DOI: 10.1177/03611981231214231
Ibrahim Elnaml, H. Dylla, Jun Liu, L. Mohammad, S. Cooper, S. Cooper
To meet the asphalt pavement industry’s net zero carbon emission goals, increasing reclaimed asphalt pavement (RAP) levels to greater than 25% is considered a critical tactic. However, many state departments of transportation are cautious in adopting high RAP content into their designs because of durability issues resulting from aged RAP binders. This paper assesses the effectiveness of using the Lewis acid catalyst, FeCl3, in improving the cracking resistance of high-RAP asphalt mixtures to meet Louisiana’s balanced mixture design (BMD) criteria, and lower embodied carbon of asphalt mixtures. Four asphalt mixtures were designed and tested against permanent deformation, intermediate- and low-temperature cracking, and durability. Mixture 1 is conventional, which contains performance grade (PG) 76-22 polymer-modified asphalt binder with no RAP. Mixture 2 is unmodified PG 67-22 and 30% RAP without catalyst. Mixtures 3 and 4 incorporated an unmodified asphalt binder PG 67-22, a catalyst, and 30% and 50% RAP, respectively. A life cycle assessment (LCA) analysis was conducted on asphalt mixtures that complied with Louisiana’s BMD specifications to quantify global warming potential improvements. Because the performance of both mixtures is expected to be similar, the scope of the LCA analysis was limited to only those life cycle stages that are expected to be different, modules A1–A3 (i.e., cradle-to-gate stages). Results showed that the use of FeCl3 can improve asphalt mixtures’ cracking resistance containing high RAP contents, whilst it did not have a negative impact on permanent deformation resistance. Further, the addition of FeCl3 to asphalt mixtures with 30% and 50% RAP levels showed a reduction in greenhouse gas emissions by 28% and 43.4%, respectively.
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