The Impact of Transport Infrastructure and Pollutant Emissions in Sustainable Tourism for Mongolia

Tourism has a positive impact on economic growth,and it is one of the rapidly growing sectors in Mongolia.The Mongolian government,focusing on the development of tourism and transportation since 1990,has made it possible for achieving continuously growing sustainable tourism.Sustainable tourism is a way of maintaining a high level of tourist satisfaction while reducing adverse impacts on the environment.As transportation has been an integral part of the tourism industry,the purpose of this study is to examine the impact of transportation infrastructure,CO2 emission,and other classical demand factors on tourism flow in Mongolia by using a gravity model.Utilizing a panel data of tourists from 30 countries with the highest number of travel visits in Mongolia from 2002 to 2018,the study employs on panel co-integration analysis,aside from the conventional pooled ordinary least squares(OLS),fixed effects,and random effects estimators,to estimate the long-run relationship between Mongolian tourism flow and their respective determinants.According to the result of this study,the local transportation system and transportation investment have came out negative due to the underdeveloped transportation system.Moreover,the research indicates that carbon dioxide emission has a positive impact on tourism flow in the long-run.

Situation and hotspot analysis on rural transport infrastructure from the perspective of bibliometric analysis

The construction of rural transportation infrastructure is of great significance to promote the organic integration of transportation construction with resource exploitation and industrial development in rural areas,and realize poverty alleviation and poverty reduction driven by convenient transportation.In order to understand the research status of rural transport infrastructure at home and abroad,this paper adopts CiteSpace,VOSviewer,Pajek,SPSS and other software and makes quantitative analysis and knowledge map drawing of the literature on rural transportation infrastructure collected in Web of Science database.The results show that the emphasis of this field is different in different periods,Chinese scholars'attention to this field increased significantly after the rural revitalization strategy was put forward.Based on the classification results of keyword clustering,the following conclusions are drawn:The planning mode of rural transportation infrastructure under rural revitalization is relatively backward and the lack of theoretical analysis of the root causes has achieved the purpose of rational allocation of transportation resources.Moreover,there are few studies on the mechanism and empirical analysis of transport infrastructure's effect on rural poverty reduction.From the analysis of research hotspots,the integration of urban and rural areas and rural road safety will be the main research direction in the future,and rural road accidents and other topics have research potential.

Integrated design of transport infrastructure and public spaces considering human behavior:A review of state-of-the-art methods and tools

In order to achieve holistic urban plans incorporating transport infrastructure,public space and the behavior of people in these spaces,integration of urban design and computer modeling is a promising way to provide both qualitative and quantitative support to decisionmakers.This paper describes a systematic literature review following a four-part framework.Firstly,to understand the relationship of elements of transport,spaces,and humans,w e review policy and urban design strategies for promoting positive interactions.Secondly,we present an overview of the integration methods and strategies used in urban design and policy discourses.Afterward,metrics and approaches for evaluating the effectiveness of integrated plan alternatives are reviewed.Finally,this paper gives a review of state-of-the-art tools with a focus on seven com puter simulation paradigms.This article explores mechanisms underlying the complex system of transport,spaces,and humans from a multidisciplinary perspective to provide an integrated toolkit for designers,planners,modelers and decision-m akers with the current methods and their challenges.

Seismic behavior of tire waste-sand mixtures for transportation infrastructure in cold regions

Tire wastes have many properties that are valuable from a geotechnical engineering perspective, such as low density, high strength, thermal insulation, energy absorption capacity, permeability, durability, compressibility, resilience, and high frictional strength. Thus, tire wastes offer good thermal characteristics in resisting frost penetration and have good drainage characteristics, being as permeable as coarse granular soil for fill materials. The many advantages of tire wastes make the material suitable for transportation infrastructure construction in cold regions. Also, tire wastes with high damping prop- erty make them a preferable admixture with sand for transportation infrastructures in seismic regions, This study aimed to determine the seismic performance of certain tire waste-sand mixtures in cold regions. A 70% sand-30% tire crumb mixture by weight （TC30） with a very high damping property was selected for analysis as an engineering material for transportation infrastructure. Small-scale shake-table tests were conducted on this material as well as on a sand-only sample under two different temperatures, 0 ℃ and 20 ℃, to simulate cold-region and moderate-temperature performance, respectively. The 1999 lzmit Earthquake Excitation （EW） （Mw = 7.4） was taken as the input motion. Test results showed that the tire waste-sand mixture at 0 ℃ showed better seismic performance than that at room temperature, suggesting that a tire waste-sand mixture in cold regions may reduce seismic hazards to infrastructure.

Upgrade of Transportation Infrastructure and Siting of Polluting Enterprises:The Case of High-Speed Railway Launch in China

With the quasi-natural experiment of the launching of high-speed railways in Chinese cities,this paper empirically investigated the effects of the upgrade of the transportation infrastructure on the site selection of polluting enterprises.We found that although the launching of a high-speed railway generally has a negative impact on the siting of polluting enterprises:(i)While there was a significant decrease in polluting enterprises of a private and other nature,the reduction in overseas-funded and state-owned enterprises was insignificant;(ii)while the launching of a high-speed railway greatly restrained the entry of polluting enterprises in the eastern region,large cities and more developed cities,this was followed by the movement of more polluting enterprises to the central and western regions,small and medium-sized cities and less developed cities;(iii)there was a significant decrease in polluting enterprises in environmentally conscious cities after the launching of a high-speed railway.This paper also found that infrastructure upgrade may influence the siting of polluting enterprises through the following:Environmental cleanness,factor concentration and spatial integration.Government authorities and market entities should be fully aware of and attach great importance to how the transportation infrastructure influences the site selection of businesses,as this is of great significance for China’s regional development planning,local business climate and investment planning,environmental protection,and other related policymaking initiatives.

Impacts of road on plant invasions in the Middle Mountain region of central Nepal

Biological invasion is triggered by human development activities such as the construction and expansion of road networks.Road verges serve as important habitats and corridors for the distribution of invasive alien plant species(IAPS)between geographically distant habitats.However,the trajectory of plant invasion and the data regarding the impact of roads on IAPS distribution are relatively poor in Nepal.Here,we surveyed two road types(main roads and feeder road)in the Middle Mountain region of central Nepal in order to investigate how different road types are driving the dispersal of IAPS along road verges and the adjacent natural habitats.Systematic sampling was conducted at ca 2.5 km intervals along the roads.At each sampling site,paired plots(25 m×4 m)were sampled:one adjacent to and along the road,and another 20 m away and parallel to it in the interior habitat.Our results revealed that the main road verges had a higher cover(33%)and a larger number of IAPS(14 species)than the feeder road(25%;10 species).The IAPS cover and richness were significantly higher along verges than in the adjacent interior habitats for both road types,indicating that roads are contributing as corridors for the dispersal of IAPS in the Middle Mountain areas of central Nepal.Further,elevation,tree canopy,and disturbances(grazing/mowing/trampling)were found to be the key factors that determine spatial distribution of IAPS along road verges.We emphasize that regular monitoring of vegetation along the road verges can help with the early detection and control of potential IAPS in the region before they become problematic.

Econometric Analysis of Transport Sector on Economic Growth in Rwanda (1999-2018)

The purpose of this study was to examine Econometric analysis of transport sector on economic growth in Rwanda for the period of 1999 up to 2018. It’s an empirical study which used econometric techniques such as unit root test, Engle granger test/cointegration test, linear regression model and the error correction model to analyze the contribution of transport sector on economic growth based on Gross Capital formation in terms of transport infrastructures, trade balance as import and export can be affected by transport system, and contribution of transport services to economic growth. This study found that, there was a strong statistically significant relationship between GDP and transport sector as measured by transport services for both short run and long run as it is shown by R-squared of 0.997316 and 0.782009 of the long run regression model and error correction model respectively. ECM showed a quick recovery of 81.3% every year after a shock happen. This study concluded that there is a short run and long run relationship between Transport service and economic growth. This study recommends that policy implication that can be deducted from this study to facilitate transport sector through expansion of road networks and maintenance of existing road networks coupled with revitalization of alternative mode of transportation such as air transport, rail system and waterways will significantly improve the growth of the

Risk Management of Large Infrastructure Projects: Risk, Uncertainty, and Complexity

The development of large infrastructure projects requires the consideration of many different risks in advance,of which the two common risks are strategic risk and project risk.This study provides an overview of the different relevant literature on risk management of large infrastructure projects.Based on the Hong Kong section of the Guangzhou-Shenzhen-Hong Kong high-speed rail,this study identified the project’s main strategic risks and project risks,and provided suggestions for risk management.

Fire hazard in transportation infrastructure:Review,assessment,and mitigation strategies

This paper reviews the fire problem in critical transportation infrastructures such as bridges and tunnels.The magnitude of the fire problem is illustrated,and the recent increase in fire problems in bridges and tunnels is highlighted.Recent research undertaken to address fire problems in transportation structures is reviewed,as well as critical factors governing the performance of those structures.Furthermore,key strategies recommended for mitigating fire hazards in bridges and tunnels are presented,and their applicability to practical situations is demonstrated through a practical case study.Furthermore,research needs and emerging trends for enhancing the“state-of-the-art”in this area are discussed.

Iterative Factors Favoring Collaboration for Interorganizational Resilience:The Case of the Greater Montréal Transportation Infrastructure

Between members of a network, interorganizational resilience is favored by effective collaboration and coordination during a crisis. The quality of that collaboration depends on various iterative factors present between these organizations before the occurrence of a crisis.We find that these factors are iterative since collaboration factors follow a mutually reinforcing cycle: collaboration within a crisis management network is conditioned by a general agreement, which is in turn conditioned by the extent to which the institutions coordinate themselves prior to crisis. We evaluated the factors that promote collaboration between public and private organizations that manage the Greater Montréal transportation infrastructure.These factors are based on adaptive management processes such as mutual agreements, common organizational culture, knowledge and financial resources, levers of power,regulations, and pressure. Crisis management coordination represents the ability to build and assess the effectiveness of common response plans to risks to which they are exposed. We show how these processes vary depending on the links between private and public organizations.

Field Observations of Near-Surface Wind Flow Across Expressway Embankment on the Qinghai–Tibet Plateau

Crushed rock layers(CRLs),ventilation ducts(VDs)and thermosyphons are air-cooling structures(ACSs)widely used for maintaining the long-term stability of engineered infrastructures in permafrost environments.These ACSs can effectively cool and maintain the permafrost subgrade’s frozen state under climate warming by facilitating heat exchange with ambient air in cold seasons.As convection is a crucial working mechanism of these ACSs,it is imperative to understand the near-surface wind flow(NSWF)across a constructed infrastructure,such as an embankment.This article describes a yearlong field observation of the NSWF across an experimental expressway embankment,the first of its kind on the Qinghai–Tibet Plateau(QTP).The wind speed and direction along a transect perpendicular to the embankment on both the windward and leeward sides and at four different heights above the ground surface were collected and analyzed.The results showed that the embankment has a considerable impact on the NSWF speed within a distance of up to ten times its height,and in the direction on the leeward side.A power law can well describe the speed profiles of NSWF across the embankment,with the power-law indices(PLIs)varying from 0.14 to 0.40.On an annual basis,the fitted NSWF PLI far away from the embankment was 0.19,which differs substantially from the values widely used in previous thermal performance evaluations of ACSs on the QTP.Finally,the significance of the NSWF to the thermal performance of the ACSs,particularly the CRLs and VDs,in linear transportation infrastructure is discussed.It is concluded that underestimating the PLI and neglecting wind direction variations may lead to unconservative designs of the ACSs.The results reported in this study can provide valuable guidance for infrastructure engineering on the QTP and other similar permafrost regions.

Spatial Structure Adjustment Strategies of the Coal Resource-Based Cities during the Mature Period: A Case Study of Pingdingshan

Coal cities are the main part of the resource-based cities in China, and the benign development of coal cities' spatial structure has a direct impact on these cities' future economic and social development, as well as the urban residents' welfare. Land use fragmentation is the most typical morphological characteristic of the coal city's spatial structure development. In this paper, Pingdingshan City of Henan Province in China is taken as an example. Through empirical analysis, the urban spatial structure development processes of a typical coal resource-based city in its mature period are illustrated, and the formation reasons and potential mechanism behind coal city land use fragmentation are explored, and the measurement method of land use fragmentation degree of the coal city is put forward. On the above basis, the appropriate adjustment strategies and methods aimed at the coal city spatial structure are found out and given. This study is a good guideline and reference for the spatial structure planning and land use planning of the coal city during the mature and declining period, which is of great help to the sustainable development and industrial structure transformation of the coal city. It also has certain reference significance for the coal city in the growth period.

Preface for the special issue on "Advanced Transportation Infrastructure and Materials"

The International Association of Chinese Infrastructure Pro- fessionals （IACIP） and Chang＇an University jointly hosted the first International Conference on Transportation Infrastruc- ture and Materials （ICTIM） in Xi＇an, China on July 16-18, 2016. This conference covered a variety of research topics on transportation infrastructure and materials, including pave- ment mechanics, geomechanics, highway materials, ground improvement, recycling materials, maintenance and rehabil- itation, intelligent construction, infrastructure management, intelligent transportation system, and risk and reliability. Over 200 participants from 11 countries participated in this conference, which included 13 presentation sessions, 2 workshops, and 1 forum.

Usability of Waste Steel Grits in Concrete Pavement

The usability of waste steel grits and limestone sand in the construction of concrete pavement was investigated.Four different types of pavement concretes were produced,including coarse limestone concrete not containing waste steel grit,coarse limestone concrete containing waste steel grit,limestone sand concrete not containing waste steel grit,and limestone sand concrete containing waste steel grit.In this study,water/binder ratio in concrete production was taken as 0.44.In the production of limestone sand concrete containing waste steel grit,limestone sand with a grain diameter of 0.1-1.0 mm was used as aggregate.Waste steel grits with a grain diameter of 0.2-0.7 mm were added to the concrete mixture.Standard water curing and combined curing were applied to concrete samples.After standard water curing and combined curing,compression and bending tests of the same types of cube and beam concrete samples were carried out.As a result of the study,the maximum compressive and bending strengths were found to be 50.21 MPa and 5.07 MPa for limestone sand concrete containing waste steel grit.The study results show that waste steel grits increase the compressive and bending strength of concrete pavement.

Laser additive manufacturing for infrastructure repair:A case study of a deteriorated steel bridge beam

As our transportation infrastructure ages,its deterioration is becoming a growing concern.Rapid and effective methods for repair can reduce the need for time-and cost-intensive replacement of structures such as roadway bridges.In this work,laser-based additive manufacturing(AM)was developed for the repair of damaged beams in steel bridges.A corroded structural beam of low-carbon A36 steel was selected for this case study and 316L stainless steel was used for repair due to its excellent mechanical properties and corrosion resistance.Simulated repair experiments were performed on specimens extracted from the beam,and prepared with various groove shapes(Rectangular,Trapezoidal,and U-shaped).More in-depth parametric and microstructural studies were carried out with a series of U-shaped specimens repaired with the linear laser input energy varied from 19.5 to 30.0 J mm–1.The tensile properties of the repaired specimens and interface structures were also investigated in detail.It was found that the repaired specimens had a slightly higher tensile strength despite a reduction in tensile elongation compared to the A36 steel base metal.The influence of interfacial microstructure and heterogeneity on the mechanical properties of the repaired specimens was discussed.Our work suggests the promising potential to employ AM for structural repair and provides fundamental insights into processing-structure-property relationships in laser AM-repaired materials.

Evolution of regional transport dominance in China 1910-2012

Transport infrastructure plays an important role in shaping the configuration of spatial socio-economic structures and influencing regional accessibility. Although China＇s transport infrastructure has been experiencing a rapid development in the last 100 years, there lacks a systematic examination of the complete evolution history of China＇s transport development, particularly with all kinds of transport modes. This paper first aims to clarify the history of China＇s transportation from 1910 to 2012, and divides its evolution process into five periods （1911, 1935, 1953, 1981 and 2012） whereby each period represents the preliminary development time for each transport mode. Second, the paper calculates the transport dominance and analyses its spatial distribution in each period, with county as the basic analysis unit. Transport dominance here is defined as an integrated indicator for evaluating regional transport conditions. The results demonstrate the following： （1） areas with relative good transport dominance have expanded from scattered dots such as Tianjin, Shanghai, Guangzhou in 1911 to extensive areas with each provincial city as cores in 2012; （2） transport development is improved by advances in transportation technology. The construction of modern transport infrastructures such as seaports, airports, high-speed rails （HSRs）, and freeways lead the expansion of national territorial areas with good and excellent transport dominance and the increase of the value of transport dominance over time; （3） transport dominance is spatially unevenly distributed and exhibits resemblance with the expansion of transport network, which is closely related to China＇s socio-economic development and policles.

The heterogeneous impact of China-Europe railway express on the efficiency of logistics industry in node cities

Purpose-The spatiotemporal compression effect of China-Europe Railway Express(CR-Express)can reduce the filow costs of resources between China's node cities.Additionally,it can break through the limitations of low-added-value marine products,significantly impacting the logistics industry efficiency.However,there are few literature verifying and analyzing its heterogeneity.This study explores the impact of CR-Express on the efficiency of logistics industry in node cities and analyzes the heterogeneity.Design/methodology/approach-First,this study uses panel data to measure the efficiency of node city logistics industry.Secondiy,this study discusses the impact of the opening of CR-Express on the efficiency of logistics industry in node cities based on the multi-period differential model.Finally,according to the node city difference,the sample city experimental group is grouped for heterogeneity analysis.Findings-The results show that CR-Express can promote the urban logistics industry efficiency,with an average effect of 4.55%.According to the urban characteristics classification,the heterogeneity analysis shows that the efficiency improvement effect of logistics industry in inland cities is more obvious.The improvement effect of node cities and central cities in central and western China is stronger,especially in the sample of megacities and type I big cities.Compared with non-value chain industrial products,the CR-Express has significant promotion effects on the logistics efficiency of the cities where main goods are value chain products.Originality/value-Under the background of double cycle development,this paper can provide a scientific basis for the investment benefit evaluation of CR-Express construction and the follow-up route planning.

Estimation of flexible pavement structural capacity using machine learning techniques

The most common index for representing structural condition of the pavement is the structural number.The current procedure for determining structural numbers involves utilizing falling weight deflectometer and ground-penetrating radar tests,recording pavement surface deflections,and analyzing recorded deflections by back-calculation manners.This procedure has two drawbacks:falling weight deflectometer and ground-penetrating radar are expensive tests;back-calculation ways has some inherent shortcomings compared to exact methods as they adopt a trial and error approach.In this study,three machine learning methods entitled Gaussian process regression,M5P model tree,and random forest used for the prediction of structural numbers in flexible pavements.Dataset of this paper is related to 759 flexible pavement sections at Semnan and Khuzestan provinces in Iran and includes“structural number”as output and“surface deflections and surface temperature”as inputs.The accuracy of results was examined based on three criteria of R,MAE,and RMSE.Among the methods employed in this paper,random forest is the most accurate as it yields the best values for above criteria(R=0.841,MAE=0.592,and RMSE=0.760).The proposed method does not require to use ground penetrating radar test,which in turn reduce costs and work difficulty.Using machine learning methods instead of back-calculation improves the calculation process quality and accuracy.

Using occupancy models to determine mammalian responses to landscape changes

Determining impacts of anthropogenic landscape changes on wildlife populations is difficult.Besides the challengesDetermining impacts of anthropogenic landscape changes on wildlife populations is difficult.Besides the challenges of designing field studies to document conditions before and after landscape changes occur,assessment of popula-of designing field studies to document conditions before and after landscape changes occur,assessment of popula-tion responses(e.g.changes in population density)often provide poor inference because of sampling limitations.tion responses(e.g.changes in population density)often provide poor inference because of sampling limitations.Estimation of occupancy,however,only requires data on detection or non-detection of a species and might provideEstimation of occupancy,however,only requires data on detection or non-detection of a species and might provide better inference.To demonstrate the utility of occupancy models,we used data from an American black bear(Ursusbetter inference.To demonstrate the utility of occupancy models,we used data from an American black bear(Ursus americanus Pallas)population in North Carolina,USA to test our research hypothesis that documented declines inamericanus Pallas)population in North Carolina,USA to test our research hypothesis that documented declines in site occupancy of black bears would be greater near a new four-lane highway.We used multi-season occupancysite occupancy of black bears would be greater near a new four-lane highway.We used multi-season occupancy models to estimate site occupancy based on bear visitation to survey sites before and after completion of the newmodels to estimate site occupancy based on bear visitation to survey sites before and after completion of the new highway and as a function of distance to the highway.Site occupancy declined from 0.81 to 0.35 between the twohighway and as a function of distance to the highway.Site occupancy declined from 0.81 to 0.35 between the two study phases,but was not a function of distance to the highway.Therefore,the impact of the new highway onstudy phases,but was not a function of distance to the highway.Therefore,the impact of the new highway on occupancy extended to the entire study area.Our case study demonstrates that occupancy models can provideoccupancy extended to the entire study area.Our case study demonstrates that occupancy models can provide powerful inference regarding the potential impacts of landscape changes on species occupancy.As urban areas andpowerful inference regarding the potential impacts of landscape changes on species occupancy.As urban areas and transportation infrastructure are rapidly expanding in developing regions of the world,the need to determine howtransportation infrastructure are rapidly expanding in developing regions of the world,the need to determine how these changes affect mammal populations and how they might be mitigated increases accordingly.Because fieldthese changes affect mammal populations and how they might be mitigated increases accordingly.Because field sampling for occupancy models only requires detection data,surveys can be conducted for extensive geographicsampling for occupancy models only requires detection data,surveys can be conducted for extensive geographic areas,thus making these surveys particularly applicable to studies of large mammals.areas,thus making these surveys particularly applicable to studies of large mammals.