In the e-commerce era, express delivery networks (EDNs) play an increasingly important role in linking intercity production and consumption. Although many studies have examined their characteristics, most rely on express origin-destination (OD) connections and overlook actual transport routes. Using large-scale waybill data, this study constructs a routing-based EDN in China and examines its spatial patterns, city functions, and community structures. The results show that although both the OD network and the EDN are dense in the east and sparse in the west, their organizational forms differ significantly. Contrasting with the diamond structure of the OD network, the EDN exhibits a more hierarchical hub-spoke structure, where dominant flows form a polycentric radial pattern. By jointly considering outflow, inflow, and transit volumes, we observe clear spatial differentiation in city functions and classify cities into eight functional types. Community analysis further reveals substantial differences in internal structure and cross-community connectivity: high-volume communities tend to be more polycentric and better connected across communities, whereas low-volume communities show stronger local dependence. These findings highlight the importance of routing information for understanding the actual organization of EDNs and provide an empirical basis for optimizing hub planning, logistics provision, and regional coordination.

Numerous studies have shown that agglomeration externalities play a crucial role in the survival prospects of logistics firms. However, previous studies have largely ignored the role that agglomeration externalities play at a more granular level. Therefore, this paper used Chengdu International Railway Port as a case study, constructed a distance-based agglomeration measure to explore the impact of agglomeration externalities on the survival of logistics firms located within a publicly developed logistics park (PDLP). The results show that the three types of agglomeration externalities coexist and are highly localized in the PDLP, and their effects change with distance from the logistics firm. Specifically, the specialization externalities operate within 1.5 km of the logistics firm and produce competitive effects within immediate proximity (0.5 km). Second, while diversification externalities cause significant congestion effects, interindustry knowledge spillovers arising from related diversification externalities play a key role in the 0.5 km proximity of logistics firms, and unrelated diversification externalities play a positive role in reducing the market transaction costs of logistics firms outside the 0.5 km range.

Front Distribution Centres (FDCs) are increasingly used by retailers to enhance service accessibility and reduce logistics costs. However, existing studies often overlook differences between online and offline models and neglect location equity. This article proposes a novel bi-objective mixed-integer programming framework for FDC location-allocation under different operational modes. To evaluate equity, the Huff model is integrated into the 2-Step Floating Catchment Area (2SFCA) method to quantify spatial accessibility under competition. The cost objective incorporates delivery and time costs to improve distribution efficiency. An efficient hybrid algorithm combining Lagrangian relaxation and Multi-Objective Whale Optimization (MOWOA) is developed to solve the NP-hard model. A case study on a fresh produce e-commerce network in Chengdu, China, shows that the optimized layout improves average accessibility by 55.05% while reducing total costs by 6.91%. This work provides an integrated framework and solution methodology offering actionable insights for designing economically efficient and socially equitable FDC networks.

Warehouses play a crucial role in freight transportation, and their pricing strategies affect warehouse location choices and associated environmental impacts. Although most firms rent storage spaces, limited studies have examined warehouse rental prices (WRP). Furthermore, most studies assume a pre-defined relationship between WRP and its correlates. This study applies spatial machine learning models to warehouse rental data in Shanghai to examine their nonlinear associations. The results show that the primary factors influencing WRP include spatial dependence among warehouses, location and neighborhood attributes, and the floor level of warehouse spaces, whereas lease and service-related factors contribute minimally. Moreover, spatial dependence leads to segmented markets, with high-rent warehouses clustering in the central urban area and around logistics parks and transportation terminals outside the central area. Additionally, most primary correlates exhibit irregular nonlinear relationships with WRP, which shed light on warehouse pricing mechanisms and provide guidance for location choices.

Existing studies on hazardous materials trucks mainly focus on route selection and risk assessment during truck movements, neglecting the potential threat to the areas which surround truck stops. In this paper, we propose a novel algorithm to identify the truck stops from GPS data based on the temporal and spatial attributes, and classify the categories of hazardous materials truck stops according to the Chinese National Economy Industry Classification System. GIS spatial analysis method is then employed to establish the temporal and spatial distribution of different categories of stops. Taking the trajectory data of hazardous materials trucks in Chengdu, China, as the sample dataset, the study shows that the trucks are mainly used in service, manufacturing, and wholesale and retail industries, and more than 80% of the stops are located outside the urban core area. Concerning stay time, nearly 60% of trucks stay in the identified areas for less than 2 h and only 20% of trucks for more than 9 h. The peak periods for the arrival of the trucks at most stops are 9–12 a.m. and 2–10 p.m., and stops on weekdays have less influence on their spatial distribution. Such results can provide decision-making support to government departments in their designation of operation sites, regulatory facilities, and transportation corridors, and transportation companies can arrange transportation routes and travel time according to the management measures thus taken.

Publicly developed logistics parks (PDLPs) have been considered one of the measures in urban logistics policies to reduce carbon emissions. In response, this paper draws on the “pollution transfer” hypothesis, constructs a carbon emission analysis framework for PDLPs, and uses spatial econometric methods to explore their carbon emission effects. The findings suggest that from a global perspective, PDLPs can lead to the emergence of “pollution havens” in the suburban and exurban areas while relieving the carbon emission burden in the urban core. Secondly, PDLPs can further contribute to forming “pollution havens” by promoting logistic re-agglomeration, and the “innovation compensation” effect of PDLPs is not significant. Finally, the carbon emission effects of PDLPs are spatiotemporally heterogeneous. A carbon reduction effect is noted when the logistic re-agglomeration in the location of PDLPs is higher, and an “innovation compensation” effect is also produced when the technological innovation is higher.

The COVID-19 pandemic has exerted unprecedented impacts on the world. Since its onset, China has established a network of fever clinics as an effective strategy to aggressively isolate and screen possible patients with COVID-19 symptoms. This study presents two fever clinic maps that visualize the uneven responses to the COVID-19 pandemic at the city level in mainland China. The maps highlight more resources in the southwest, northwest, east, and south China, and paucity in the far west parts of southwest and northwest China and in the north and northeast China.

公共物流设施是物流活动的主要承载区域,对促进物流业高质量发展和降本增效具有积极意义.科学规划大城市公共物流设施有利于优化城市空间布局、扩大内需市场、保障民生消费和增强应急物流保障能力,但现有政策实践有关公共物流设施规划的原则、规划要点和转型方向尚不清晰.本文从大城市公共物流设施规划发展历程认识入手,系统总结了典型公共物流设施规划的重点和差异,从空间布局、设施融合、产业支撑、绿色发展和安全韧性视角,提出了公共物流设施规划的经验原则与内在要求;结合国家"十四五"规划的新要求,从创新、协调、绿色、开放、共享发展视角,指出了新时期公共物流设施规划的转型方向与实施策略.

The complex landforms of a Shan-shui City (Shan-shui refers to mountains and rivers) significantly impact the selection of locations for logistics enterprises. This paper takes Chongqing, one of the most typical Shan-shui Cities in China, as the research object, and adopts spatial analysis methods and a mediating effect model, to explore the role of mountains and rivers in the formation of logistics enterprises' spatial pattern on the street scale. The study results reveal that 90% of the logistics enterprises in the central urban areas of Chongqing are located in the low-altitude area below 353m above sea level, and distributed in a north-south direction along the mountains, as a result of blockage by mountain ranges, such as those of Zhongliang Mountain and Tongluo Mountain. More than 70% of the logistics enterprises are located less than 5 km from either the Yangtze River or Jialing River, spreading along the rivers. In addition, more than half of the logistics enterprises in commercial and financial, and residential land are located within the urban core area, while 80.83% of the logistics enterprises located in warehousing land and industrial land are concentrated in the urban expansion area. In areas with high land prices, the negative effect of altitude on logistics enterprise agglomeration is weakened, while the promotion effect of river proximity on logistics enterprise agglomeration is enhanced. In the urban core area with the advantage of low altitude and proximity to the Jialing and Yangtze Rivers, the role of mountains and rivers on logistics enterprises is not apparent; in contrast, in the urban expansion area with more complex landforms, land price can be an effective means for the government to macro-manage the spatial pattern of logistics enterprises in a Shan-shui City.

Logistics clusters play an essential role in bridging production and consumption. Researchers, government authorities, and investors have widely recognized the benefits of logistics agglomeration, and extensive research on this topic has been performed in recent years. The aim of this study is to present an intellectual landscape through a structured literature review of logistics cluster research. First, following the logic of "what-why-how", we found that logistics cluster research can be divided into three parts: the concept and quantitative identification of logistics clusters, the agglomeration externalities of logistics clusters, and the competitiveness and growth mechanism of logistics clusters. Second, the bibliometric results indicate that: (i) logistics clusters have gradually developed from an engineering or operations management discipline into one involving multidisciplinary approaches of geosciences, sustainable science, etc.; (ii) the focus of research has gradually shifted from the development and operation of logistics clusters to the exploration of the clusters growth mechanism; (iii) researchers start to concentrate on spatially explicit analyses of the economic and environmental effects of logistics clusters, and the exploration of sustainable growth paths for clusters. Finally, in consideration of these trends and the emerging situation, we propose some new research topics, such as (i) the convergence and competitive effect of logistics clusters, (ii) data science and analytics in logistics clusters, (iii) the application of new theories and technologies to transportation and supply chain, etc. in logistics cluster scenarios, (iv) sustainable operation of logistics clusters, and (v) quantitative modeling research in logistics clusters. Overall, much room is left for theoretically and practically expanding logistics cluster research. This study can further the unveiling of the systemic nature of logistics cluster research and provide new insights for scholars, practitioners and policymakers.

This paper aims to explore the relationship between logistics firm size and business diversification, especially in micro- and small-sized enterprises, and assess the diversification process of Chongqing logistics enterprises using new data source. It is intended to contribute to theoretical research on diversification in the emerging logistics industry based on resource-based view (RBV) and factor production theory. We innovatively establish the logistics business classification system, then measure the degree and direction of diversification of logistics enterprises based on mean narrow-spectrum diversification-based product count methods. The empirically shows that there are a growing number of highly-diversified logistics enterprises in general, with an average annual increase of 14.23%. Especially after 2008, small and medium-sized enterprises developed towards related diversification while micro-sized enterprises came to the opposite conclusion. For them, creating unrelated diversified business is a crucial way to generate a competitive advantage. Unlike the conclusions derived from other industries, small-sized logistics enterprises are prone to try a new business, both related and unrelated, for better survival and performance. And changes in the firm size of medium and large-sized enterprises have little impact on the development of the business diversification.

This study provides insights into the spatial relationships among logistics agglomeration, technological progress, and air pollution in the sub-regions. From the perspective of new economic geography, the positive environmental externality of logistics agglomeration should outstrip its negative externality as the result of technological spillover. However, significant impacts of technological progress on the environment have not been identified in the logistics agglomeration sub-regions of many developing countries currently grappling with various environmental problems. This paper applies spatial econometrics and extended STIRPAT model to explore the roles the logistics agglomeration (LA) and technological progress (T) play in air pollution (I) using panel data from sub-regions of Chongqing in China between 2009 and 2019. The main conclusions are as follows. (1) In a global context, logistics agglomeration is a meaningful way to reduce air pollution under the interaction effect of technological progress. (2) In a sub-regional context: first, the suppressive effect of logistics agglomeration on air pollution gradually rebounds with the increase in agglomeration degree; secondly, the rebound effect of technological innovation is also evident in air pollution, and the rebound area gradually spreads from the metropolitan area to the peripheral sub-regions; finally, the interaction effect of logistics agglomeration and technological progress has a noteworthy suppression effect on air pollution, especially after the occurrence of the rebound effect of the logistics agglomeration and technological progress. In this regard, local governments should suppress the negative externalities of agglomeration with the interaction effects of technological progress while strengthening logistics agglomeration.

Nowadays, the application of location-aware devices, such as global positioning system (GPS)-enabled mobile phones and personal digital assistants (PDAs) is increasing. Based on this, a new demand for efficiently storing trajectory data has arisen. Trajectory compression reduces the storage space and cost, the cost and time of data transmission by retaining critical trajectory points and effectively eliminating redundant data. Herein, a novel trajectory compression method based on stay points (TCSP) is proposed. By using the road network data and the stay points of GPS trajectory data to compress the GPS trajectory data, this method can greatly improve the ratio and accuracy of compression. Experimental results based on real data sets show that the compression rate of this method can stably reach 8.61%, and the compression effect can be restored to the original trajectory route. Compared with the critical point algorithm and the Douglas–Peucker (DP) algorithm, the TCSP method can reach a better compression effect and compression ratio.

Background The current 2019 coronavirus disease (COVID-19) pandemic is hitting citizen’s life and health like never before, with its significant loss to human life and a huge economic toll. In this case, the fever clinics (FCs) were still preserved as one of the most effective control measures in China, but this work is based on experience and lacks scientific and effective guidance. Here, we use travel time to link facilities and populations at risk of COVID-19 and identify the dynamic allocation of patients’ medical needs, and then propose the optimized allocation scheme of FCs. Methods We selected Shenzhen, China, to collect geospatial resources of epidemic communities (ECs) and FCs to determine the ECs’ cumulative opportunities of visiting FCs, as well as evaluate the rationality of medical resources in current ECs. Also, we use the Location Set Covering Problem (LSCP) model to optimize the allocation of FCs and evaluate efficiency. Results Firstly, we divide the current ECs into 3 groups based on travel time and cumulative opportunities of visiting FCs within 30 min: Low-need communities (22.06%), medium-need communities (59.8%), and high-need communities (18.14%) with 0,1–2 and no less than 3 opportunities of visiting FCs. Besides, our work proposes two allocation schemes of fever clinics through the LSCP model. Among which, selecting secondary and above hospitals as an alternative in Scheme 1, will increase the coverage rate of hospitals in medium-need and high-need communities from 59.8% to 80.88%. In Scheme 2, selecting primary and above hospitals as an alternative will increase the coverage rate of hospitals in medium-need and high-need communities to 85.29%, with the average travel time reducing from 22.42 min to 17.94 min. Conclusions The optimized allocation scheme can achieve two objectives: a. equal access to medical services for different types of communities has improved while reducing the overutilization of high-quality medical resources. b. the travel time for medical treatment in the community has reduced, thus improving medical accessibility. On this basis, during the early screening in prevention and control of the outbreak, the specific suggestions for implementation in developing and less developed countries are made.

The highway network is considered to be an effective solution for reducing regional differences and promoting high-quality economic development. This study mapped Sichuan’s highway network on an equal per capita GDP cartogram and on an equal highway freight volumes cartogram, which can provide a unique perspective to recognize the rationality of highway layouts and its coordination relationship with the population and economic development. The research result indicates that highway layouts are seriously affected by the topographical and geologic conditions, and the population and level of economic development are key influencing factors. It also shows that the density of the highway network is still seriously inadequate in the vast mountain and plateau area.

基于重庆市5 937家物流企业,采用物流企业生态位模型和计数模型,从多尺度甄别物流企业优势区位及影响因素.结果 表明:①在区县尺度上,生态位宽度处于高中低水平的区县分别有8、8、22个,围绕主城区和万州区呈现“一主一副”的空间结构;②在街道尺度上,物流企业密度处于前3层的29个街道中仅有1个街道的物流企业态处于前3层,物流企业密度处于后3层的413个街道中有29个街道的物流企业态处于前3层,态值与密度空间分布总体不协调,高密度低态值问题突出;③商品交易市场交易额和是否有物流节点布局与物流企业数量高度正相关,不受规模影响;对物流企业规模加权后,工业产值被是否有港口布局因素取代.

Work zones exist widely in cities of many countries and have a significant negative impact on city traffic. The majority of the existing studies only focused on freeway work zones, while the work zones on urban arterials have not been investigated carefully. For the first time, this paper focuses on a specific type of work zone that is located within the area of the intersection, namely, the island work zone, and proposes a novel model for the traffic flow of the island work zone based on the social force theory. Compared to the existing traffic-flow models, such as the car-following and lane-changing models, the proposed model can capture the special characteristics of the traffic flow in the island work zone, such as heterogeneity, no lane division, and irregular boundary. The field data collected in Chengdu, China, are used to calibrate and validate the proposed model. Simulations are also conducted to investigate the variations of traffic-flow characteristics for different work zone features. The results display that the model can replicate the heterogeneous traffic flow of the intersection with island work zone with high performance. When an island work zone is located close to the intersection approach, it will significantly block the entrance of vehicles. When the work zone occupies over 1 m of the median divider, its impact on the traffic flow will become very significant.

The train collision dynamic theory is an acceptable method for new vehicle design, which can save a great deal of simulation and experimentation. A train collision dynamic model that considers the longitudinal and vertical coupling is established. The vehicle subsystem and the track subsystem are also considered in the model through the function of the link between the wheel/rail subsystems and the coupler buffer/anti-climber subsystems. The entire train model is analyzed with a coupled feedback system. The dynamic simulation program of the coupled system is developed, the calculation flow of the coupled model is given, and the explicit time domain solution of the model is realized. Two numerical examples with the same kind of vehicle were completed, and the numerical results are compared with the finite element simulation results. The results show that the coupled model is not only close to the finite element model but also greatly shortens the solution time of the collision response. The accuracy and theory of the collision dynamics model in this article are verified. The results of the paper provide new theoretical evidence and a simulation method for further research on the design of the crashworthiness of rail vehicle structures and the collision dynamic evolution during a train collision.

The logistics clusters are the result of concentration, scale and specialization of logistics activities, and their quantitative measurement and development evaluation provide an important foundation for improving the land use efficiency and achieving economies of scale. Taking 289 cities at prefecture-level and above as research objects, this paper collected macro-statistical data of transport, postal and warehousing industry during 2000-2014, business registration data of more than 290 thousand logistics enterprises, and 170 thousand logistics points of interest (POI). With the integration of multi-index and multi-source data, the evolution process and spatial pattern of logistics clusters in China were explored with the methods of Location Quotient (LQ), Horizontal Cluster Location Quotient (HCLQ), Logistics Employment Density (LED) and modified Logistics Establishments' Participation (LEP). The development levels, types and modes of different logistics clusters were quantified. Several important findings are derived from the study. (1) The logistics clusters are mainly located on the east side of the Hu Huanyong Line, and the accumulative pattern evolves from group to block structure, featuring wide coverage and high concentration. The evolution of logistics clusters has two stages of rapid convergence and stable change, resulting in gradual increase in the development level and efficiency of logistics clusters and in emergence of spil-lover effect. (2) 21 mature logistics clusters are distributed in the core and sub-cities of the main metropolitan areas of 16 provincial-level administrative divisions, conforming to the government logistics and transport planning. 43 emerging logistics clusters are distributed in 21 provincial administrative divisions, and different types of cities have huge disparities which highlight the differentiation of the market behaviors and government planning among them. (3) The logistics clusters present differentiated development modes with the change of scales. In urban agglomerations scale, the nested "center-periphery" structures with "main nucleus-secondary cores-general nodes" are clarified. The polar nuclear development, networked and balanced development, single core and multipoint, multi-core multipoint hub-spoke development patterns are formed in different provincial administrative divisions.