The traffic speed deflectometer (TSD) overcomes the limitations of the falling weight deflectometer (FWD) with respect to traffic interruption and test inefficiency and is considered the preferred method for network-level pavement structural evaluation. However, some challenges exist when applying the TSD to routine survey work. This study evaluated the long-term repeatability of TSDs and compared TSD measurements with FWD measurements to examine device-related errors in TSD measurements. In addition, a framework for incorporating TSD measurements into the pavement management system (PMS) was developed by introducing deflection bowl parameters (DBPs). All data analyses were based on TSD data collected in Tennessee. From the current study, the repeatability of the TSD has not been fully validated because of device-related errors. Since TSD measurements and FWD measurements are broadly similar, periodic validation of TSDs by FWDs is recommended for quality control. TSDs provide valuable information about pavement structural conditions that are not reliably or adequately reflected in the current PMS (which focuses mainly on pavement functional conditions). DBPs are a simple and fast method for making initial estimates of pavement structural conditions without the need for layer thickness. In the proposed DBP system, the surface curvature index (SCI_12) and D60 (TSD deflection at 60 in. before the load center) represent the structural strength of the asphalt layer and subgrade, respectively. The combination of pavement functional conditions and TSD-measured structural conditions (PMS+DBPs) may help to make more accurate predictions of pavement performance and to make more appropriate decisions on maintenance and rehabilitation strategies.
{"title":"Traffic Speed Deflectometer for Network-Level Pavement Management in Tennessee","authors":"Miaomiao Zhang, Xiaoyang Jia, Guozhi Fu, Pawel Andrzej Polaczyk, Yuetan Ma, Rui Xiao, Baoshan Huang","doi":"10.1177/03611981231197665","DOIUrl":"https://doi.org/10.1177/03611981231197665","url":null,"abstract":"The traffic speed deflectometer (TSD) overcomes the limitations of the falling weight deflectometer (FWD) with respect to traffic interruption and test inefficiency and is considered the preferred method for network-level pavement structural evaluation. However, some challenges exist when applying the TSD to routine survey work. This study evaluated the long-term repeatability of TSDs and compared TSD measurements with FWD measurements to examine device-related errors in TSD measurements. In addition, a framework for incorporating TSD measurements into the pavement management system (PMS) was developed by introducing deflection bowl parameters (DBPs). All data analyses were based on TSD data collected in Tennessee. From the current study, the repeatability of the TSD has not been fully validated because of device-related errors. Since TSD measurements and FWD measurements are broadly similar, periodic validation of TSDs by FWDs is recommended for quality control. TSDs provide valuable information about pavement structural conditions that are not reliably or adequately reflected in the current PMS (which focuses mainly on pavement functional conditions). DBPs are a simple and fast method for making initial estimates of pavement structural conditions without the need for layer thickness. In the proposed DBP system, the surface curvature index (SCI_12) and D60 (TSD deflection at 60 in. before the load center) represent the structural strength of the asphalt layer and subgrade, respectively. The combination of pavement functional conditions and TSD-measured structural conditions (PMS+DBPs) may help to make more accurate predictions of pavement performance and to make more appropriate decisions on maintenance and rehabilitation strategies.","PeriodicalId":23279,"journal":{"name":"Transportation Research Record","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135015021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To provide an equitable transportation system for the public, it is vital to fully understand underrepresented populations’ active transportation needs and their challenges. This study is designed to identify the active transportation studies that focus on underrepresented populations, evaluate the quantification approaches used in the literature, and uncover barriers to the use of active transportation among underrepresented populations in the United States. We used PRISMA guidelines to systematically review relevant publications. After screening and reviewing the literature, some 60 articles were included in the review. The most frequent results when reviewing the literature include that active travel and daily transport trips decreased from younger to older age groups; bicycling was more popular among men, White, and individuals with higher education, whereas walking was more popular among women; bike usage was found to be low among minorities, and those with lower incomes. Furthermore, communities with poor accessibility to bike infrastructure had a larger concentration of African Americans, Hispanics, Asians, low-wage employees, individuals with lower education, and older adults.
{"title":"Active Transportation for Underrepresented Populations in the United States: A Systematic Review of Literature","authors":"Eazaz Sadeghvaziri, Ramina Javid, Mansoureh Jeihani","doi":"10.1177/03611981231197659","DOIUrl":"https://doi.org/10.1177/03611981231197659","url":null,"abstract":"To provide an equitable transportation system for the public, it is vital to fully understand underrepresented populations’ active transportation needs and their challenges. This study is designed to identify the active transportation studies that focus on underrepresented populations, evaluate the quantification approaches used in the literature, and uncover barriers to the use of active transportation among underrepresented populations in the United States. We used PRISMA guidelines to systematically review relevant publications. After screening and reviewing the literature, some 60 articles were included in the review. The most frequent results when reviewing the literature include that active travel and daily transport trips decreased from younger to older age groups; bicycling was more popular among men, White, and individuals with higher education, whereas walking was more popular among women; bike usage was found to be low among minorities, and those with lower incomes. Furthermore, communities with poor accessibility to bike infrastructure had a larger concentration of African Americans, Hispanics, Asians, low-wage employees, individuals with lower education, and older adults.","PeriodicalId":23279,"journal":{"name":"Transportation Research Record","volume":"232 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135306570","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-09-16DOI: 10.1177/03611981231195052
Marvin V. Baumann, Magdalena Schilling, Markus Friedrich, Sebastian Reichert, Peter Vortisch, Volker Wassmuth
This paper extends the concept of a design hourly volume (DHV) which is derived from the “ nth hour” to a concept based on the nth highest saturated hour. To calculate this nth highest saturated hour at each ramp junction of a node, it is necessary to have permanent traffic counts (PTC) on all ramps and the main lanes. In practice, such counts are often not available. For such cases, the German Highway Capacity Manual proposes a method that enables the estimation of DHV through short-term traffic counts (STCs) and the extrapolation of the results using available PTC in the vicinity. This study examines how accurately the required nth highest saturated hour can be estimated with this method and similar concepts. Furthermore, we investigate to what extent the number and the location of the available PTC affect the accuracy of the estimation. Scenarios without PTC are also considered. The evaluation is based on a database with a total of 72 freeway nodes for which PTC data from three years (2017–2019) are processed. The results show that the estimation of the nth highest saturated hour with the method of the German Highway Capacity Manual works accurately, even if only one PTC is available on each inflowing approach. The results further indicate that STC are crucial to achieve accurate results when few PTCs are available. Acceptable results are also obtained by STC of one week, even without a projection at a PTC.
{"title":"Design Hourly Volume Estimation at Freeway Nodes From Short-Term Traffic Counts","authors":"Marvin V. Baumann, Magdalena Schilling, Markus Friedrich, Sebastian Reichert, Peter Vortisch, Volker Wassmuth","doi":"10.1177/03611981231195052","DOIUrl":"https://doi.org/10.1177/03611981231195052","url":null,"abstract":"This paper extends the concept of a design hourly volume (DHV) which is derived from the “ nth hour” to a concept based on the nth highest saturated hour. To calculate this nth highest saturated hour at each ramp junction of a node, it is necessary to have permanent traffic counts (PTC) on all ramps and the main lanes. In practice, such counts are often not available. For such cases, the German Highway Capacity Manual proposes a method that enables the estimation of DHV through short-term traffic counts (STCs) and the extrapolation of the results using available PTC in the vicinity. This study examines how accurately the required nth highest saturated hour can be estimated with this method and similar concepts. Furthermore, we investigate to what extent the number and the location of the available PTC affect the accuracy of the estimation. Scenarios without PTC are also considered. The evaluation is based on a database with a total of 72 freeway nodes for which PTC data from three years (2017–2019) are processed. The results show that the estimation of the nth highest saturated hour with the method of the German Highway Capacity Manual works accurately, even if only one PTC is available on each inflowing approach. The results further indicate that STC are crucial to achieve accurate results when few PTCs are available. Acceptable results are also obtained by STC of one week, even without a projection at a PTC.","PeriodicalId":23279,"journal":{"name":"Transportation Research Record","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135307291","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-09-16DOI: 10.1177/03611981231196146
Liuqingcheng Niu, Sike Gao, Jinlei Shi, Changxu Wu, Yuwei Wang, Shu Ma, Duming Wang, Zhen Yang, Hongting Li
Head-up display (HUD) warnings are gaining increasing attention with the growing importance of advanced warning systems in vehicles for improving driving safety. However, the effectiveness of HUD warnings is still controversial considering the various driving performance indexes, warning modalities, and driving scenarios used in previous studies. This study conducts meta-analyses of the relevant literature to examine whether HUD warnings (both unimodal HUD warnings and multimodal warnings with HUD) have advantages compared with other warnings (head-down display warnings, auditory warnings, tactile warnings, and multimodal warnings without HUD) for driver reaction times and driving quality. Overall, 33 articles were included in four meta-analyses. Additionally, the effects of the related moderator variables of scenario, mapping of warnings, and non-driving-related tasks (NDRTs) on the relationship between using HUD warnings and using non-HUD warnings was analyzed. The results show that using unimodal HUD warnings leads to faster reaction times compared with head-down display warnings but has no significant advantage on driving performance over auditory warnings in general and results in slower reaction times than using tactile warnings. However, results of the moderating effects suggest that using HUD warnings in non-critical scenarios and using high mapping HUD icons (i.e., HUD warnings with specific hazard information) are conducive to improving driving performance in comparison with other warning types. These results highlight the potential advantages of HUD in transmitting warning information. The future application and design of HUD warnings may need to focus on specific situations considering iconic mapping to an event.
{"title":"Are Warnings Suitable for Presentation in Head-Up Display? A Meta-Analysis for the Effect of Head-Up Display Warning on Driving Performance","authors":"Liuqingcheng Niu, Sike Gao, Jinlei Shi, Changxu Wu, Yuwei Wang, Shu Ma, Duming Wang, Zhen Yang, Hongting Li","doi":"10.1177/03611981231196146","DOIUrl":"https://doi.org/10.1177/03611981231196146","url":null,"abstract":"Head-up display (HUD) warnings are gaining increasing attention with the growing importance of advanced warning systems in vehicles for improving driving safety. However, the effectiveness of HUD warnings is still controversial considering the various driving performance indexes, warning modalities, and driving scenarios used in previous studies. This study conducts meta-analyses of the relevant literature to examine whether HUD warnings (both unimodal HUD warnings and multimodal warnings with HUD) have advantages compared with other warnings (head-down display warnings, auditory warnings, tactile warnings, and multimodal warnings without HUD) for driver reaction times and driving quality. Overall, 33 articles were included in four meta-analyses. Additionally, the effects of the related moderator variables of scenario, mapping of warnings, and non-driving-related tasks (NDRTs) on the relationship between using HUD warnings and using non-HUD warnings was analyzed. The results show that using unimodal HUD warnings leads to faster reaction times compared with head-down display warnings but has no significant advantage on driving performance over auditory warnings in general and results in slower reaction times than using tactile warnings. However, results of the moderating effects suggest that using HUD warnings in non-critical scenarios and using high mapping HUD icons (i.e., HUD warnings with specific hazard information) are conducive to improving driving performance in comparison with other warning types. These results highlight the potential advantages of HUD in transmitting warning information. The future application and design of HUD warnings may need to focus on specific situations considering iconic mapping to an event.","PeriodicalId":23279,"journal":{"name":"Transportation Research Record","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135308605","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-09-16DOI: 10.1177/03611981231195053
Qiong Hu, Amir Mehdizadeh, Alexander Vinel, Miao Cai, Steven E. Rigdon, Wenbin Zhang, Fadel M. Megahed
With more and more data related to driving, traffic, and road conditions becoming available, there has been renewed interest in predictive modeling of traffic incident risk and corresponding risk factors. New machine learning approaches in particular have recently been proposed, with the goal of forecasting the occurrence of either actual incidents or their surrogates, or estimating driving risk over specific time intervals, road segments, or both. At the same time, as evidenced by our review, prescriptive modeling literature (e.g., routing or truck scheduling) has yet to capitalize on these advancements. Indeed, research into risk-aware modeling for driving is almost entirely focused on hazardous materials transportation (with a very distinct risk profile) and frequently assumes a fixed incident risk per mile driven. We propose a framework for developing data-driven prescriptive optimization models with risk criteria for traditional trucking applications. This approach is combined with a recently developed machine learning model to predict driving risk over a medium-term time horizon (the next 20 min to an hour of driving), resulting in a biobjective shortest path problem. We further propose a solution approach based on the k-shortest path algorithm and illustrate how this can be employed.
{"title":"Shortest Path Problems with a Crash Risk Objective","authors":"Qiong Hu, Amir Mehdizadeh, Alexander Vinel, Miao Cai, Steven E. Rigdon, Wenbin Zhang, Fadel M. Megahed","doi":"10.1177/03611981231195053","DOIUrl":"https://doi.org/10.1177/03611981231195053","url":null,"abstract":"With more and more data related to driving, traffic, and road conditions becoming available, there has been renewed interest in predictive modeling of traffic incident risk and corresponding risk factors. New machine learning approaches in particular have recently been proposed, with the goal of forecasting the occurrence of either actual incidents or their surrogates, or estimating driving risk over specific time intervals, road segments, or both. At the same time, as evidenced by our review, prescriptive modeling literature (e.g., routing or truck scheduling) has yet to capitalize on these advancements. Indeed, research into risk-aware modeling for driving is almost entirely focused on hazardous materials transportation (with a very distinct risk profile) and frequently assumes a fixed incident risk per mile driven. We propose a framework for developing data-driven prescriptive optimization models with risk criteria for traditional trucking applications. This approach is combined with a recently developed machine learning model to predict driving risk over a medium-term time horizon (the next 20 min to an hour of driving), resulting in a biobjective shortest path problem. We further propose a solution approach based on the k-shortest path algorithm and illustrate how this can be employed.","PeriodicalId":23279,"journal":{"name":"Transportation Research Record","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135307957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-09-16DOI: 10.1177/03611981231196151
Md. Fazle Rabbi, Rakan Alturk, Radim Bruzek, Theodore R. Sussmann, Hugh B. Thompson, Debakanta Mishra
Strain gauges are often used to measure vertical wheel loads in a railroad track. This approach is based on the concept of differential-shear-strain (DSS) measurement: The difference in vertical shear force between two points along a beam equals the magnitude of the resultant of applied vertical forces in between. With a slight modification to the strain-gauge positions and installation of an additional set of strain gauges, this concept can be extended to measure the vertical rail–tie interface reaction forces, thus assessing the tie support conditions. Although the application of DSS measurements for vertical-wheel-load quantification is widely prevalent in the railroad community, the validity of this approach for tie reaction measurement has been relatively unexplored. Conceptually, the approach is similar to the vertical-wheel-load measurement system, with the only difference being the placement of the strain gauges along the rail. Nevertheless, several questions have been raised about how different track and loading configurations can affect the accuracy of such a measurement system. To address some of these concerns and establish this approach as a viable method for tie support condition assessment, a field-validation effort was undertaken. Under the scope of this research effort, the strain-gauge-based DSS measurement system for rail–tie interface reaction-force measurement was evaluated in the field under static as well as dynamic loading. The study showed that the strain-gauge-based measurement approach is as accurate as other conventional methods of tie reaction-force measurement.
{"title":"Response of Strain-Gauge-Based Tie Reaction Measurement Circuits under Dynamic Loading and Variable Support Conditions","authors":"Md. Fazle Rabbi, Rakan Alturk, Radim Bruzek, Theodore R. Sussmann, Hugh B. Thompson, Debakanta Mishra","doi":"10.1177/03611981231196151","DOIUrl":"https://doi.org/10.1177/03611981231196151","url":null,"abstract":"Strain gauges are often used to measure vertical wheel loads in a railroad track. This approach is based on the concept of differential-shear-strain (DSS) measurement: The difference in vertical shear force between two points along a beam equals the magnitude of the resultant of applied vertical forces in between. With a slight modification to the strain-gauge positions and installation of an additional set of strain gauges, this concept can be extended to measure the vertical rail–tie interface reaction forces, thus assessing the tie support conditions. Although the application of DSS measurements for vertical-wheel-load quantification is widely prevalent in the railroad community, the validity of this approach for tie reaction measurement has been relatively unexplored. Conceptually, the approach is similar to the vertical-wheel-load measurement system, with the only difference being the placement of the strain gauges along the rail. Nevertheless, several questions have been raised about how different track and loading configurations can affect the accuracy of such a measurement system. To address some of these concerns and establish this approach as a viable method for tie support condition assessment, a field-validation effort was undertaken. Under the scope of this research effort, the strain-gauge-based DSS measurement system for rail–tie interface reaction-force measurement was evaluated in the field under static as well as dynamic loading. The study showed that the strain-gauge-based measurement approach is as accurate as other conventional methods of tie reaction-force measurement.","PeriodicalId":23279,"journal":{"name":"Transportation Research Record","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135308599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-09-14DOI: 10.1177/03611981231195051
Ayobami Adewale, Chris Lee
Autonomous vehicles (AVs) have moved from hype to reality as the penetration and acceptance rate continues to increase. As they are slowly integrated into traffic with human-driven vehicles (HDVs), it is necessary to predict the car-following behaviors of AVs and HDVs for better control of AV–HDV mixed traffic. This study extends a data-driven car-following model to incorporate drivers’ memory, and cooperation with the lead vehicle. The model predicts the following vehicle’s speed in AV–HDV mixed traffic. The effect of drivers’ cooperation on car-following behavior was modeled using prospect theory (PT), whereas the driver’s memory was incorporated using the memory cell of a long short-term memory (LSTM) neural network. This extended car-following model is called the “PT-LSTM model.” Real-world vehicle trajectories of HDVs and AVs in the Waymo AV Open Dataset were used to calibrate and validate the PT-LSTM model. The PT-LSTM model demonstrated higher accuracy compared with the LSTM model that did not consider drivers’ cooperation, the multiple layer perceptron model, Gipps’ model, and the intelligent driver model that incorporated PT. The importance of variables in different time steps in the PT-LSTM model was also evaluated using SHapley Additive exPlanations (SHAP). The SHAP results showed that AV followers were more likely to cooperate with the lead HDV, whereas HDV followers were more likely to cooperate with the lead AV than the lead HDV. Thus, this study underscores the importance of considering drivers’ memory and cooperation with the lead vehicle for the prediction of car-following behaviors in AV–HDV mixed traffic.
{"title":"Prediction of Car-Following Behavior of Autonomous Vehicle and Human-Driven Vehicle Based on Drivers’ Memory and Cooperation With Lead Vehicle","authors":"Ayobami Adewale, Chris Lee","doi":"10.1177/03611981231195051","DOIUrl":"https://doi.org/10.1177/03611981231195051","url":null,"abstract":"Autonomous vehicles (AVs) have moved from hype to reality as the penetration and acceptance rate continues to increase. As they are slowly integrated into traffic with human-driven vehicles (HDVs), it is necessary to predict the car-following behaviors of AVs and HDVs for better control of AV–HDV mixed traffic. This study extends a data-driven car-following model to incorporate drivers’ memory, and cooperation with the lead vehicle. The model predicts the following vehicle’s speed in AV–HDV mixed traffic. The effect of drivers’ cooperation on car-following behavior was modeled using prospect theory (PT), whereas the driver’s memory was incorporated using the memory cell of a long short-term memory (LSTM) neural network. This extended car-following model is called the “PT-LSTM model.” Real-world vehicle trajectories of HDVs and AVs in the Waymo AV Open Dataset were used to calibrate and validate the PT-LSTM model. The PT-LSTM model demonstrated higher accuracy compared with the LSTM model that did not consider drivers’ cooperation, the multiple layer perceptron model, Gipps’ model, and the intelligent driver model that incorporated PT. The importance of variables in different time steps in the PT-LSTM model was also evaluated using SHapley Additive exPlanations (SHAP). The SHAP results showed that AV followers were more likely to cooperate with the lead HDV, whereas HDV followers were more likely to cooperate with the lead AV than the lead HDV. Thus, this study underscores the importance of considering drivers’ memory and cooperation with the lead vehicle for the prediction of car-following behaviors in AV–HDV mixed traffic.","PeriodicalId":23279,"journal":{"name":"Transportation Research Record","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134911545","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-09-13DOI: 10.1177/03611981231189747
H. M. Imran Kays, Arif Mohaimin Sadri, K. K. “Muralee” Muraleetharan, P. Scott Harvey, Gerald A. Miller
The significance of critical infrastructure systems in maintaining productivity is undeniable. However, such systems remain susceptible to external disturbances and cascading failures. Instead of operating independently, these physical systems, such as transportation and stormwater systems, form an interdependent system. This interdependence, particularly important during flooding, illustrates that the failure of a stormwater system can disrupt traffic networks. To explore the extent of such interdependency, this study investigates the transportation and stormwater networks in Norman, Oklahoma. Using network science theories and concepts of multilayered networks, this paper analyzes these systems, both individually and in combination. The study identifies closely located components in the road and stormwater networks using Moran's I spatial autocorrelation metric. Next, the connectivity of these networks is represented in a graph format to investigate the topological credentials (i.e., rank of relative importance) of the network components (i.e., water inlets, road intersections as nodes, and stormwater conduits, road segments as links). Moreover, such credentials further change by considering the weights of the network components (i.e., average daily traffic, water flow). The proximity-based connectivity considerations between these networks utilizing Moran's I significance score revealed a good indicator of spatial interdependency. When incorporating directionality, the multilayer network analysis highlights that highly central components tend to cluster spatially, unlike the undirected counterpart. The study also identifies vulnerable locations and network components in a combined network setting that differ from the networks in isolation. In doing so, the research reveals new insights governing the complex reliance of transportation systems on neighboring stormwater systems.
{"title":"Exploring the Interdependencies Between Transportation and Stormwater Networks: The Case of Norman, Oklahoma","authors":"H. M. Imran Kays, Arif Mohaimin Sadri, K. K. “Muralee” Muraleetharan, P. Scott Harvey, Gerald A. Miller","doi":"10.1177/03611981231189747","DOIUrl":"https://doi.org/10.1177/03611981231189747","url":null,"abstract":"The significance of critical infrastructure systems in maintaining productivity is undeniable. However, such systems remain susceptible to external disturbances and cascading failures. Instead of operating independently, these physical systems, such as transportation and stormwater systems, form an interdependent system. This interdependence, particularly important during flooding, illustrates that the failure of a stormwater system can disrupt traffic networks. To explore the extent of such interdependency, this study investigates the transportation and stormwater networks in Norman, Oklahoma. Using network science theories and concepts of multilayered networks, this paper analyzes these systems, both individually and in combination. The study identifies closely located components in the road and stormwater networks using Moran's I spatial autocorrelation metric. Next, the connectivity of these networks is represented in a graph format to investigate the topological credentials (i.e., rank of relative importance) of the network components (i.e., water inlets, road intersections as nodes, and stormwater conduits, road segments as links). Moreover, such credentials further change by considering the weights of the network components (i.e., average daily traffic, water flow). The proximity-based connectivity considerations between these networks utilizing Moran's I significance score revealed a good indicator of spatial interdependency. When incorporating directionality, the multilayer network analysis highlights that highly central components tend to cluster spatially, unlike the undirected counterpart. The study also identifies vulnerable locations and network components in a combined network setting that differ from the networks in isolation. In doing so, the research reveals new insights governing the complex reliance of transportation systems on neighboring stormwater systems.","PeriodicalId":23279,"journal":{"name":"Transportation Research Record","volume":"155 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135742017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-09-11DOI: 10.1177/03611981231193417
Sohil Paudel, Matthew Vechione, Okan Gurbuz
Parking demand at university campuses has been an issue for decades and is gradually increasing each year. With limited capacity, space, and funds to expand parking facilities, there is a dire need to better understand parking behavior on a university campus so that universities can better utilize the limited resources available. One methodology that has been used by Metropolitan Planning Organizations to predict traveler behavior is known as travel demand modeling, where the most common modeling technique is a four-step procedure that utilizes socioeconomic data to predict current and future traffic volumes in a network (e.g., a city). This study focuses primarily on the trip generation step, and The University of Texas at Tyler campus was used as a case study. First, each parking lot on campus was assigned to a parking demand zone (PDZ) based on its proximity to classroom buildings, and the hourly arrival demand for each PDZ was measured using pneumatic tube counters. The course schedule and floor space utilization data for each building on campus were then extracted as input parameters to predict the parking demand at each PDZ. A linear regression model and two artificial neural network (ANN) frameworks were developed. One ANN model was recommended, as it had an R-squared value of 0.846. From the selected ANN model, an equation has been extracted, which has the potential to be used by course schedulers to modify the course schedule to better mitigate parking demand on campus without the need to develop new parking facilities.
{"title":"Predicting University Campus Parking Demand Using Machine Learning Models","authors":"Sohil Paudel, Matthew Vechione, Okan Gurbuz","doi":"10.1177/03611981231193417","DOIUrl":"https://doi.org/10.1177/03611981231193417","url":null,"abstract":"Parking demand at university campuses has been an issue for decades and is gradually increasing each year. With limited capacity, space, and funds to expand parking facilities, there is a dire need to better understand parking behavior on a university campus so that universities can better utilize the limited resources available. One methodology that has been used by Metropolitan Planning Organizations to predict traveler behavior is known as travel demand modeling, where the most common modeling technique is a four-step procedure that utilizes socioeconomic data to predict current and future traffic volumes in a network (e.g., a city). This study focuses primarily on the trip generation step, and The University of Texas at Tyler campus was used as a case study. First, each parking lot on campus was assigned to a parking demand zone (PDZ) based on its proximity to classroom buildings, and the hourly arrival demand for each PDZ was measured using pneumatic tube counters. The course schedule and floor space utilization data for each building on campus were then extracted as input parameters to predict the parking demand at each PDZ. A linear regression model and two artificial neural network (ANN) frameworks were developed. One ANN model was recommended, as it had an R-squared value of 0.846. From the selected ANN model, an equation has been extracted, which has the potential to be used by course schedulers to modify the course schedule to better mitigate parking demand on campus without the need to develop new parking facilities.","PeriodicalId":23279,"journal":{"name":"Transportation Research Record","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135980792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2023-09-11DOI: 10.1177/03611981231194629
Brian Lassy, Alexandra Hain, Arash E. Zaghi, Zoltan M. Kanyo, Bao K. Chuong, Andrew Cardinali
Beam end corrosion is one of the most prominent types of deterioration on simple-span steel bridges. To address this concern, the Connecticut Department of Transportation and the University of Connecticut have jointly developed a repair method for corroded steel girder ends using ultra-high-performance concrete (UHPC) encasement. In this repair, shear studs are welded to the undamaged portion of the web and encased in UHPC to create an alternate load path for bearing and shear forces. This novel repair method has been implemented in multiple states. The widespread promotion of steel girder end repair with UHPC demonstrates the need for literature on field implementations and alternative designs. This paper advances the findings from a field implementation completed in Connecticut in October 2021, which was the first instance of a partial-height repair in the country, the first application of the repair to a weathering steel bridge, and the first use of flange studs to restore shear capacity at the junction of the web and bottom flange. Two of the girder ends were fully instrumented to collect data on the performance of the repaired locations. The paper presents an overview of the bridge, discusses the design and implementation of the repair, provides short-term monitoring data showing its successful activation, and discusses lessons learned throughout the process. It is anticipated that the findings put forward provide support for the use of UHPC encasement as a promising method for the repair of corroded steel girder ends.
{"title":"Rehabilitation of Corroded Steel Bridge Girder Ends using Partial-Height Ultra-High-Performance Concrete Encasement","authors":"Brian Lassy, Alexandra Hain, Arash E. Zaghi, Zoltan M. Kanyo, Bao K. Chuong, Andrew Cardinali","doi":"10.1177/03611981231194629","DOIUrl":"https://doi.org/10.1177/03611981231194629","url":null,"abstract":"Beam end corrosion is one of the most prominent types of deterioration on simple-span steel bridges. To address this concern, the Connecticut Department of Transportation and the University of Connecticut have jointly developed a repair method for corroded steel girder ends using ultra-high-performance concrete (UHPC) encasement. In this repair, shear studs are welded to the undamaged portion of the web and encased in UHPC to create an alternate load path for bearing and shear forces. This novel repair method has been implemented in multiple states. The widespread promotion of steel girder end repair with UHPC demonstrates the need for literature on field implementations and alternative designs. This paper advances the findings from a field implementation completed in Connecticut in October 2021, which was the first instance of a partial-height repair in the country, the first application of the repair to a weathering steel bridge, and the first use of flange studs to restore shear capacity at the junction of the web and bottom flange. Two of the girder ends were fully instrumented to collect data on the performance of the repaired locations. The paper presents an overview of the bridge, discusses the design and implementation of the repair, provides short-term monitoring data showing its successful activation, and discusses lessons learned throughout the process. It is anticipated that the findings put forward provide support for the use of UHPC encasement as a promising method for the repair of corroded steel girder ends.","PeriodicalId":23279,"journal":{"name":"Transportation Research Record","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135980922","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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