A new energy-efficient control strategy for intelligent track inspection trains (ITITs) was developed and its effectiveness evaluated. A sufficiently simple state-space model for a real ITIT is introduced in this paper. This model was used to formulate and solve a constrained optimisation problem to determine the vehicle's optimal speed profile using the pseudo-spectral method to achieve the highest energy savings. A model predictive control (MPC) scheme was then used to create a controller to follow the resulting optimal speed trajectory as closely as possible. The results obtained from co-simulation between a high-fidelity model of the ITIT built within the Amesim software program and the MPC scheme developed in the Matlab/Simulink software environment showed that the optimal speed trajectory was tracked very well when the MPC scheme was applied to the vehicle's high-fidelity model. During the co-simulations, the energy consumption in terms of the battery's state of charge (SOC) changes for the MPC-based optimal speed trajectory following was around 6% less than that for a conventional non-optimal cruise controller. Moreover, in an experiment with a real ITIT, the energy consumption in terms of the SOC changes for the non-optimal cruise controller was 5% more than that for the MPC-based optimal speed trajectory following.
{"title":"Energy-optimal control of intelligent track inspection trains: design and experiment","authors":"Xinxin Zhao, Xu Guo, Nasser L. Azad, Jue Yang","doi":"10.1680/jtran.22.00077","DOIUrl":"https://doi.org/10.1680/jtran.22.00077","url":null,"abstract":"A new energy-efficient control strategy for intelligent track inspection trains (ITITs) was developed and its effectiveness evaluated. A sufficiently simple state-space model for a real ITIT is introduced in this paper. This model was used to formulate and solve a constrained optimisation problem to determine the vehicle's optimal speed profile using the pseudo-spectral method to achieve the highest energy savings. A model predictive control (MPC) scheme was then used to create a controller to follow the resulting optimal speed trajectory as closely as possible. The results obtained from co-simulation between a high-fidelity model of the ITIT built within the Amesim software program and the MPC scheme developed in the Matlab/Simulink software environment showed that the optimal speed trajectory was tracked very well when the MPC scheme was applied to the vehicle's high-fidelity model. During the co-simulations, the energy consumption in terms of the battery's state of charge (SOC) changes for the MPC-based optimal speed trajectory following was around 6% less than that for a conventional non-optimal cruise controller. Moreover, in an experiment with a real ITIT, the energy consumption in terms of the SOC changes for the non-optimal cruise controller was 5% more than that for the MPC-based optimal speed trajectory following.","PeriodicalId":49670,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Transport","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135399246","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}
Accident-prone sections are usually the most dangerous areas on a freeway, and identifying and studying them is of great significance. In this study, accident-prone sections were estimated using a 77-km long freeway section as an example located in Zhejiang province, China. This research obtained accident data and horizontal alignment data of the freeway and used two statistical methods, namely the improved cumulative frequency method considering equivalent accident numbers and the accident matrix method, to identify the accident-prone sections of the freeway. Additionally, a new method that combines vehicle dynamic simulation (using CarSIM) and speed consistency theory was introduced and used to estimate the accident-prone sections of this freeway. Furthermore, an accident prediction model was established by analyzing the relationships between the horizontal alignment geometric parameters and accident data to provide design advice. The results show that the new method has certain reliability, making it applicable for designers to verify the safety condition of newly-designed freeway and help enhance freeway security. The established model is logically reasonable and has certain precision, which can provide a valuable reference for freeway designers.
{"title":"Estimating freeway accident-prone sections: research on vehicle dynamic simulation and accident prediction model","authors":"Yi Hu, Yonghong Yang, Jian Liu, Minglei Bai","doi":"10.1680/jtran.23.00016","DOIUrl":"https://doi.org/10.1680/jtran.23.00016","url":null,"abstract":"Accident-prone sections are usually the most dangerous areas on a freeway, and identifying and studying them is of great significance. In this study, accident-prone sections were estimated using a 77-km long freeway section as an example located in Zhejiang province, China. This research obtained accident data and horizontal alignment data of the freeway and used two statistical methods, namely the improved cumulative frequency method considering equivalent accident numbers and the accident matrix method, to identify the accident-prone sections of the freeway. Additionally, a new method that combines vehicle dynamic simulation (using CarSIM) and speed consistency theory was introduced and used to estimate the accident-prone sections of this freeway. Furthermore, an accident prediction model was established by analyzing the relationships between the horizontal alignment geometric parameters and accident data to provide design advice. The results show that the new method has certain reliability, making it applicable for designers to verify the safety condition of newly-designed freeway and help enhance freeway security. The established model is logically reasonable and has certain precision, which can provide a valuable reference for freeway designers.","PeriodicalId":49670,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Transport","volume":"45 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-06-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90790353","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}
Several fire safety benefits are realised when considering autonomous vehicles (AVs) using parking buildings. Hazards posed by the increasing number of alternatively powered vehicles on the road, such as electric vehicles (EVs), may be mitigated. Parking AVs in designated zones would allow for the installation of fire-suppression systems other than those that are water-based, permit alternative ventilation requirements and allow for the reconfiguration of the building structure. Connected AVs could communicate with other vehicles, the parking building and the emergency services, resulting in a more effective response to a developing fire incident. However, AVs may increase fire safety hazards when considering alternative parking arrangements that promote more extensive fire spread, increase the median fire load energy density by at least 13% and inhibit firefighting. This may impact on the operational capability of the emergency services and the expectations of the structural fire safety design of the building. In this paper, options are presented that would influence the design and use of parking buildings where AVs and EVs are present. Presently, it is unclear whether the introduction of AVs will increase or decrease the fire safety risk to life and property, and further research is suggested to better understand such matters.
{"title":"An overview of the impacts of autonomous vehicles on fire safety in parking buildings","authors":"Michael Spearpoint, Stephen Dickson","doi":"10.1680/jtran.22.00028","DOIUrl":"https://doi.org/10.1680/jtran.22.00028","url":null,"abstract":"Several fire safety benefits are realised when considering autonomous vehicles (AVs) using parking buildings. Hazards posed by the increasing number of alternatively powered vehicles on the road, such as electric vehicles (EVs), may be mitigated. Parking AVs in designated zones would allow for the installation of fire-suppression systems other than those that are water-based, permit alternative ventilation requirements and allow for the reconfiguration of the building structure. Connected AVs could communicate with other vehicles, the parking building and the emergency services, resulting in a more effective response to a developing fire incident. However, AVs may increase fire safety hazards when considering alternative parking arrangements that promote more extensive fire spread, increase the median fire load energy density by at least 13% and inhibit firefighting. This may impact on the operational capability of the emergency services and the expectations of the structural fire safety design of the building. In this paper, options are presented that would influence the design and use of parking buildings where AVs and EVs are present. Presently, it is unclear whether the introduction of AVs will increase or decrease the fire safety risk to life and property, and further research is suggested to better understand such matters.","PeriodicalId":49670,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Transport","volume":"92 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136370893","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}
Jérémie A. Alagbé, Cheng Xu, Rujie Wang, Sheng Jin
The use of mobile phones by drivers while stopped at red traffic lights represents a potential threat due to the cognitive residuals from recent phone use. This paper presents the results of a study that investigated the rates, strategies, and activities of phone use in this situation using both video-based naturalistic and online questionnaire data, and analyzed its significant influencing factors. The study found that about 37% of drivers used their phones at traffic lights, and the majority (85%) of phone use was initiated at intersections, suggesting the relevance of phone use to traffic lights. The questionnaire data revealed that the main purpose of phone use at red lights is social media (32%), followed by text messaging (19%) and map navigation (13%), with the phone ringing, boredom, and habit being the main reasons for engaging in such activities. The logistic regression model identified waiting time, time of day, driver's age, vehicle category, vehicle value, driver's license age, and the presence of passengers as predictors for phone use. Policymakers and driver educators can find useful information in this paper to enforce laws and educate drivers to ensure safety and efficiency at signalized intersections, thus avoiding potential accidents.
{"title":"The intersection of phones and traffic lights: an analysis of usage and contributing factors","authors":"Jérémie A. Alagbé, Cheng Xu, Rujie Wang, Sheng Jin","doi":"10.1680/jtran.23.00012","DOIUrl":"https://doi.org/10.1680/jtran.23.00012","url":null,"abstract":"The use of mobile phones by drivers while stopped at red traffic lights represents a potential threat due to the cognitive residuals from recent phone use. This paper presents the results of a study that investigated the rates, strategies, and activities of phone use in this situation using both video-based naturalistic and online questionnaire data, and analyzed its significant influencing factors. The study found that about 37% of drivers used their phones at traffic lights, and the majority (85%) of phone use was initiated at intersections, suggesting the relevance of phone use to traffic lights. The questionnaire data revealed that the main purpose of phone use at red lights is social media (32%), followed by text messaging (19%) and map navigation (13%), with the phone ringing, boredom, and habit being the main reasons for engaging in such activities. The logistic regression model identified waiting time, time of day, driver's age, vehicle category, vehicle value, driver's license age, and the presence of passengers as predictors for phone use. Policymakers and driver educators can find useful information in this paper to enforce laws and educate drivers to ensure safety and efficiency at signalized intersections, thus avoiding potential accidents.","PeriodicalId":49670,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Transport","volume":"18 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82472479","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}
Cycle infrastructure provides a means for everyday travel by a mode which is efficient, benign to the environment and confers health benefits on the user. The UK Department for Transport has a funding stream dedicated to providing grants to English highway authorities to construct cycle infrastructure in accordance with guidance in Local Transport Note 1/20 Cycle Infrastructure Design. The guidance was published in 2020 and is beginning to be used widely. This paper investigates the challenges of applying the guidance. Thirteen semi-structured interviews were undertaken with politicians, managers, engineers, and cycle users. While there is ambition to deliver appropriate schemes, and there is an inspectorate, Active Travel England, to assist in ensuring the schemes comply with the guidance, there are constraints revealed by the participants. These include the limitations of short-term and medium scale funding preventing larger scale outcomes, lack of understanding of the extent to which a designer can adopt relaxations from the guidance, and skills shortages. It is encouraging to find that participants were aware of the fundamental need to separate cycle traffic both from motor traffic, and from pedestrians.
{"title":"The challenges of applying cycling design guidance","authors":"L. Hancock, J. Parkin","doi":"10.1680/jtran.22.00068","DOIUrl":"https://doi.org/10.1680/jtran.22.00068","url":null,"abstract":"Cycle infrastructure provides a means for everyday travel by a mode which is efficient, benign to the environment and confers health benefits on the user. The UK Department for Transport has a funding stream dedicated to providing grants to English highway authorities to construct cycle infrastructure in accordance with guidance in Local Transport Note 1/20 Cycle Infrastructure Design. The guidance was published in 2020 and is beginning to be used widely. This paper investigates the challenges of applying the guidance. Thirteen semi-structured interviews were undertaken with politicians, managers, engineers, and cycle users. While there is ambition to deliver appropriate schemes, and there is an inspectorate, Active Travel England, to assist in ensuring the schemes comply with the guidance, there are constraints revealed by the participants. These include the limitations of short-term and medium scale funding preventing larger scale outcomes, lack of understanding of the extent to which a designer can adopt relaxations from the guidance, and skills shortages. It is encouraging to find that participants were aware of the fundamental need to separate cycle traffic both from motor traffic, and from pedestrians.","PeriodicalId":49670,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Transport","volume":"8 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73364008","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}
Train critical components play an important role in ensuring the safety and high-speed running of trains. Failure of critical components will affect the normal operation of trains, or even cause serious accidents, resulting in economic losses, the manufacturing process of which is important to ensure life and reliability of trains. Especially, the design and manufacture of large, complex, and precise punch die is the critical technology for the manufacture of train components. In the process of extrusion, the die of the punch is at high temperature, which has a bad influence on the processing accuracy and reliability of train components. Also, hot compound deformation due to long punch stroke will reduce the life of punch die, which can increase the train manufacturing costs. Therefore, ensuring the cooling of the punch die timely is important to ensure the machining accuracy. In this study, a cooling strategy of punch die under hot compound extrusion of critical components of the trains is proposed. A numerical simulation of the cooling process of critical components of the trains is carried out to assist the optimization design of the extrusion die, and the extrusion process parameters are adjusted to cooling temperature and rate of the die. Firstly, the theoretical temperature rise of the punch die is carried out. Then, the formula of the temperature rises and cooling of the punch are obtained. Secondly, according to the forced convective heat transfer of cooling water, we calculate the convective heat transfer coefficients on the surface of the cooling pipe. Meanwhile, the interior and external heat dissipation of punch is simulated by finite element simulation. Thirdly, production beat and parameters of compound extrusion is calculated. On this basis, we design and develop a piece of interior circulation cooling cycle equipment. Finally, an example of an engineering experiment is given. The variations of the temperature field distribution are obtained after the punch extrusion and heat dissipation through the infrared temperature measuring equipment. The experiment results agree with the theoretical ones.
{"title":"The study on the cooling strategy of punch dies under hot compound extrusion of critical components of trains","authors":"Li Pan, Yongqiang Guo","doi":"10.1680/jtran.23.00015","DOIUrl":"https://doi.org/10.1680/jtran.23.00015","url":null,"abstract":"Train critical components play an important role in ensuring the safety and high-speed running of trains. Failure of critical components will affect the normal operation of trains, or even cause serious accidents, resulting in economic losses, the manufacturing process of which is important to ensure life and reliability of trains. Especially, the design and manufacture of large, complex, and precise punch die is the critical technology for the manufacture of train components. In the process of extrusion, the die of the punch is at high temperature, which has a bad influence on the processing accuracy and reliability of train components. Also, hot compound deformation due to long punch stroke will reduce the life of punch die, which can increase the train manufacturing costs. Therefore, ensuring the cooling of the punch die timely is important to ensure the machining accuracy. In this study, a cooling strategy of punch die under hot compound extrusion of critical components of the trains is proposed. A numerical simulation of the cooling process of critical components of the trains is carried out to assist the optimization design of the extrusion die, and the extrusion process parameters are adjusted to cooling temperature and rate of the die. Firstly, the theoretical temperature rise of the punch die is carried out. Then, the formula of the temperature rises and cooling of the punch are obtained. Secondly, according to the forced convective heat transfer of cooling water, we calculate the convective heat transfer coefficients on the surface of the cooling pipe. Meanwhile, the interior and external heat dissipation of punch is simulated by finite element simulation. Thirdly, production beat and parameters of compound extrusion is calculated. On this basis, we design and develop a piece of interior circulation cooling cycle equipment. Finally, an example of an engineering experiment is given. The variations of the temperature field distribution are obtained after the punch extrusion and heat dissipation through the infrared temperature measuring equipment. The experiment results agree with the theoretical ones.","PeriodicalId":49670,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Transport","volume":"176 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73188202","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}
This work aims to clarify if electric-powered aviation can comply with the requirements from the Danish government for a zero-emission carbon footprint by 2030 for domestic flight routes. The battery types were presented trying to answer if electric air transportation can be commercially viable. The gap in evaluating the feasibility of moving via electric aircrafts by 2030 was met via this research, since the feasibility under the current developments to deliver enough energy in terms of Wh/kg versus the conventional fuel for a combustion-driven aircraft was analyzed. The calculations, based on Li-Ion batteries with an energy density of 260Wh/kg, showed that the goals will be met only with the development of new battery technology. According to the results again, there will be a reduction in CO2 by approx. 17%. According to the aircraft manufacturers, it will be possible to fit up to 186 passengers in a fully electric-driven aircraft, which can meet the demand for domestic flights in Denmark. Other types of batteries, such as Li-S and Li-O2 will be relevant to investigate because of their higher energy density and usage of other natural minerals than just Lithium.
{"title":"Electric domestic aviation. Is the Danish case feasible?","authors":"Ali Fahad Dahham, Christian Rønn Olsen, G. Xydis","doi":"10.1680/jtran.22.00090","DOIUrl":"https://doi.org/10.1680/jtran.22.00090","url":null,"abstract":"This work aims to clarify if electric-powered aviation can comply with the requirements from the Danish government for a zero-emission carbon footprint by 2030 for domestic flight routes. The battery types were presented trying to answer if electric air transportation can be commercially viable. The gap in evaluating the feasibility of moving via electric aircrafts by 2030 was met via this research, since the feasibility under the current developments to deliver enough energy in terms of Wh/kg versus the conventional fuel for a combustion-driven aircraft was analyzed. The calculations, based on Li-Ion batteries with an energy density of 260Wh/kg, showed that the goals will be met only with the development of new battery technology. According to the results again, there will be a reduction in CO2 by approx. 17%. According to the aircraft manufacturers, it will be possible to fit up to 186 passengers in a fully electric-driven aircraft, which can meet the demand for domestic flights in Denmark. Other types of batteries, such as Li-S and Li-O2 will be relevant to investigate because of their higher energy density and usage of other natural minerals than just Lithium.","PeriodicalId":49670,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Transport","volume":"22 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90212216","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}
P. Pitka, Tatjana Kovačević, Milan Simeunović, Milja Simeunović, Andrijana Jovic
As service quality in any sector is determined by its users, their input must be taken into account when evaluating freight transport services. However, as transport service quality can only be evaluated following its use, and the criteria considered by the customers may differ from those deemed relevant by the experts, carrier selection process is highly complex. This research was conducted in order to provide transport service users with a simple decision making mechanism for selecting the most optimal freight carrier among multiple alternatives. The model utility is assessed by applying it to a real case, as a part of which a comprehensive sensitivity analysis is conducted to confirm its robustness.
{"title":"Estimation of transport service quality using an ordinal priority model","authors":"P. Pitka, Tatjana Kovačević, Milan Simeunović, Milja Simeunović, Andrijana Jovic","doi":"10.1680/jtran.22.00104","DOIUrl":"https://doi.org/10.1680/jtran.22.00104","url":null,"abstract":"As service quality in any sector is determined by its users, their input must be taken into account when evaluating freight transport services. However, as transport service quality can only be evaluated following its use, and the criteria considered by the customers may differ from those deemed relevant by the experts, carrier selection process is highly complex. This research was conducted in order to provide transport service users with a simple decision making mechanism for selecting the most optimal freight carrier among multiple alternatives. The model utility is assessed by applying it to a real case, as a part of which a comprehensive sensitivity analysis is conducted to confirm its robustness.","PeriodicalId":49670,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Transport","volume":"45 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81230164","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}
This study employs a hotspot areas-based data envelopment analysis (DEA) to investigate the coupling efficiency between bike-sharing demand and land use. Hotspot areas are used as decision-making units and resampling data is imposed spatial constraints. The elbow method is used to select the crucial indicators after exploring the correlation between coupling efficiency evaluation indexes using the gray correlation model. Since this coupling efficiency evaluation belongs to a “multi-input and single-output” system, DEA was introduced to build a quantitative model for bike-sharing demand & land-use coupling efficiency. This paper also identifies the factors that restrict bike-sharing demand generation. More importantly, different spatial scenarios are deployed to demonstrate heterogeneous characteristics of DEA efficiency in different locations. The results of the Beijing case show that DEA efficiency generally shows a trend from low to high from the inside out of the urban center. The land-use factors with relatively high redundancy rates are Financial Insurance Facilities, Hotels, and Living Facilities.
{"title":"Coupling efficiency between bike-sharing demand and land-use: data envelopment analysis","authors":"Chaoxu Sun, Jian Lu","doi":"10.1680/jtran.23.00003","DOIUrl":"https://doi.org/10.1680/jtran.23.00003","url":null,"abstract":"This study employs a hotspot areas-based data envelopment analysis (DEA) to investigate the coupling efficiency between bike-sharing demand and land use. Hotspot areas are used as decision-making units and resampling data is imposed spatial constraints. The elbow method is used to select the crucial indicators after exploring the correlation between coupling efficiency evaluation indexes using the gray correlation model. Since this coupling efficiency evaluation belongs to a “multi-input and single-output” system, DEA was introduced to build a quantitative model for bike-sharing demand & land-use coupling efficiency. This paper also identifies the factors that restrict bike-sharing demand generation. More importantly, different spatial scenarios are deployed to demonstrate heterogeneous characteristics of DEA efficiency in different locations. The results of the Beijing case show that DEA efficiency generally shows a trend from low to high from the inside out of the urban center. The land-use factors with relatively high redundancy rates are Financial Insurance Facilities, Hotels, and Living Facilities.","PeriodicalId":49670,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Transport","volume":"3 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80808303","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}
Baozhen Yao, Sixuan Chen, Xiaoqi Nie, Ankun Ma, Mingheng Zhang
How to accurately predict Short-term traffic travel time is an important problem in Intelligent Transportation Systems. However, the traffic data usually exhibit high nonlinearities and complex patterns. Predicting traffic travel time is a challenge. Most previous studies use the topological adjacency of road networks to explore the spatial correlations. However, as a real network, the road network contains higher-order connectivity patterns, which have different statistical significance. The topology adjacency cannot reflect these higher-order connectivity patterns. To obtain topological adjacency and higher-order connection pattern information, a novel deep learning framework was proposed: Multiple Motifs Graph Convolutional Recurrent Neural Networks, for traffic travel time prediction in this paper. The accuracy of travel time prediction can be improved by the proposed model. To be more specific, there are two meaning blocks in each unit of the model: (1) The spatial blocks captured spatial patterns information by the Multi-Motif graph convolution network and Motif Graph embedding; (2) The temporal blocks captured temporal patterns information by the combination of LSTM and the FC layer. To prove the effectiveness and accuracy of the prediction model, experiments were conducted on real world traffic travel time datasets.
{"title":"Multiple Motifs graph convolutional recurrent neural networks: a deep learning framework for short-term traffic travel time prediction","authors":"Baozhen Yao, Sixuan Chen, Xiaoqi Nie, Ankun Ma, Mingheng Zhang","doi":"10.1680/jtran.23.00006","DOIUrl":"https://doi.org/10.1680/jtran.23.00006","url":null,"abstract":"How to accurately predict Short-term traffic travel time is an important problem in Intelligent Transportation Systems. However, the traffic data usually exhibit high nonlinearities and complex patterns. Predicting traffic travel time is a challenge. Most previous studies use the topological adjacency of road networks to explore the spatial correlations. However, as a real network, the road network contains higher-order connectivity patterns, which have different statistical significance. The topology adjacency cannot reflect these higher-order connectivity patterns. To obtain topological adjacency and higher-order connection pattern information, a novel deep learning framework was proposed: Multiple Motifs Graph Convolutional Recurrent Neural Networks, for traffic travel time prediction in this paper. The accuracy of travel time prediction can be improved by the proposed model. To be more specific, there are two meaning blocks in each unit of the model: (1) The spatial blocks captured spatial patterns information by the Multi-Motif graph convolution network and Motif Graph embedding; (2) The temporal blocks captured temporal patterns information by the combination of LSTM and the FC layer. To prove the effectiveness and accuracy of the prediction model, experiments were conducted on real world traffic travel time datasets.","PeriodicalId":49670,"journal":{"name":"Proceedings of the Institution of Civil Engineers-Transport","volume":"46 1","pages":""},"PeriodicalIF":0.8,"publicationDate":"2023-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81356205","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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